“You never forget your first love” is a cliché for a reason. A first love is, indeed, bound to have some lasting psychological implications. That’s something clinical psychologist Lilly Jay, Psy.D., has experienced personally amid her divorce from her high school sweetheart, Broadway star Ethan Slater—who is now dating Ariana Grande.

Jay recently penned an essay in New York Magazine about her very public divorce. Despite Jay’s desire to maintain privacy in her personal life, the split became tabloid fodder due to Slater’s relationship with Grande. For Jay, that means her ex-husband’s new girlfriend is at the center of the Wicked movie publication cycle.

“Days with my son are sunny,” Jay writes. “Days when I can’t escape the promotion of a movie associated with the saddest days of my life are darker.”

In the vulnerable and insightful essay, Jay documents the grief of losing her private persona and the process of moving on from a first love. But even if you’re not going through a divorce from your high school sweetheart who is dating an international superstar, many types of relationships create lingering memories. According to relationship experts, there are many romantic scenarios where you might have an emotional attachment to an ex. It’s not uncommon to wonder why you can’t get over your ex whenever you hear that song.

“In relationships, there are a host of bonding experiences that can emotionally cement partners and make breakups difficult to bear in the short-term and long-term,” says clinical psychologist Carla Marie Manly, PhD, author of Date Smart. “Even when a romance has run its course and partners feel a sense of closure with the relationship, thoughts of a former partner can bubble up because the memories still exist.”

Naturally, those memories are likely to be more poignant in someone who had particularly strong feelings for an ex, “whether it was a long-term romance or more of a fling,” says Dr. Manly. In either case, those intense feelings can stick around and be resurrected years down the line by even the simplest trigger, she adds, such as a fragrance or, yes, a song.

Outside of experiencing this type of big love and then losing it, however, there are several factors related to your personality, and to the nature of a given relationship that can make it stick in your memory, no matter how much time has passed. Read on for the most common psychological reasons why you might feel like you can’t get over your ex, and how to move forward.

Why is it so hard to forget my ex?

1. The breakup *really* wasn’t mutual

“The overwhelming majority of people who are hung up on a breakup did not initiate the breakup,” says relationship expert Jess Carbino, PhD, former sociologist for Tinder and Bumble. Being on the receiving end of the breakup means they’ve had less time to “move through the uncoupling process,” she says.

While the other party “planned the breakup and had time to prepare for the goodbye and ending, you’re not only grieving the loss of the relationship, but also, you’re dealing with the shock of the news or disappointment,” says sex and relationship therapist Juliana Hauser, PhD, LMFT.

“You’re not only grieving the loss of the relationship, but also, you’re dealing with the shock of the news or disappointment.” —Juliana Hauser, PhD, LMFT, sex and relationship therapist

Not being able to understand the reason behind your ex’s choice to end things can also make it tougher to distance yourself, psychologically, from them, adds Dr. Carbino. And getting this intel might not be as simple as just asking them because sometimes, “the initiator doesn’t necessarily understand why they wanted to leave the relationship themselves, or they don’t want to reveal this information in order to spare their former partner from hurt,” she says.

The result is a gray area that can allow lingering memories of an ex to surface (and resurface), says Dr. Manly. Lacking any real sense of closure, “the psyche can take years to process, understand, and heal from a breakup,” she says.

2. The relationship ended amid unresolved issues

Closely linked to a lack of closure around a relationship’s end is the feeling that a relationship was simply cut off too soon, without time to resolve underlying issues—which often means there are unresolved emotions, too. “It can be really difficult to stop recurring thoughts about a relationship when you feel that certain aspects of the relationship were not dealt with at all or thoroughly enough,” says Dr. Hauser. Perhaps you regret saying or doing certain things in the relationship, and it ended before you could seek forgiveness.

“When the psyche feels that something has been left undone, it often works overtime—whether through dreams or ruminating about ‘what ifs’—to understand what occurred,” says Dr. Manly. “The mind wants to figure out how things could have turned out differently, so it recycles old material as it tries to reach a conclusion.” But in reality, there’s often no conclusion to reach after a sudden breakup, says Dr. Manly. There are typically too many loose ends to tie things up neatly in a bow.

3. You’re imagining what might have been

A relationship that ended too soon in your mind could also leave you lamenting “what might have been” for months or years after the fact, says Dr. Manly, and fantasizing about these coulda-woulda-shoulda scenarios.

This is common after a short-term relationship breakup, which often occurs in the “imagination stage,” when both people are still filling in the blanks about their new partner and envisioning a particular future with them, says Dr. Carbino. When that kind of relationship ends, you could be left grieving not only the loss of the person in your life but of the illusion of how things might have worked out. Managing both losses could be why you can’t forget your ex, even if your romance was brief or inconsequential in the scheme of things.

4. Your ex seriously hurt you and showed no remorse

Feeling especially hurt by the actions of an ex in any way, shape, or form is certainly one reason why their memory could stick in your mind. For example, situations where betrayal (as in infidelity) or abuse was at the root of the relationship’s dissolution could lead you to struggle with forgetting an ex, says Dr. Carbino.

And that’s particularly true if your ex didn’t seek to make amends, says Dr. Hauser. “In this case, you could feel deeply confused or disappointed by their seeming lack of remorse,” she says, “and may even imagine conversations with them or reimagine conversations you did have with them where things end differently.” At the same time, you may also “grieve that they didn’t value you enough to make things right with you or to apologize after the relationship ended,” she adds.

5. The breakup is the latest iteration of a repeating pattern

If a particular breakup takes the same shape as one that happened before it, it can draw attention to an internal conflict that you need to resolve.

“People typically choose the people that they date in order to complete the psychological arc that they started with their parents, in terms of attachment,” says Dr. Carbino. “So if you continually date the same kind of person and it doesn’t work out, you may be left frustrated about why this is happening and how these relationships are driving your psychological arc forward.”

6. There was major social fallout from the breakup

In some cases, a breakup isn’t just two people splitting; it’s a whole group of friends, colleagues, and/or acquaintances being pushed to two sides of a chasm. “This can create real social consequences, if not implications, for both people,” says Dr. Carbino.

Perhaps you lose friends, or there’s a noticeable change in your social reality or status. Or maybe even your perception of yourself changes as you can no longer identify with being someone’s partner, says Dr. Carbino. These ripple effects could make it tough to compartmentalize the breakup and leave you feeling like your ex is still influencing your life long after they’re gone.

7. Your ex was part of big life moments

“Relationships can linger in our minds for a while due to the deep emotional impact they had,” says psychotherapist and relationship expert Rebecca Marcus, LCSW. Sharing core memories or significant life events—maybe they were at your college graduation or attended your sister’s wedding—can strengthen that impact and contribute to a relationship’s lasting imprint.

It’s not necessarily a bad thing that your ex was attached to certain life events. (Heck, it probably felt great to share those experiences with them at the time.) But now, they’re wound up in each of the memories you hold of those experiences, and as a result, reminders of them may come more easily than you’d like.

8. Your ex is still in your world

Whether you still see their Instagram stories or other social posts, or even see them IRL at events hosted by mutual friends, having your ex in your sphere is going to keep them on your mind, says Marcus. No matter what you do to distance yourself from thoughts of them, these reminders are bound to surface lingering memories or bouts of relationship nostalgia.

The reality is, if you’re struggling with getting your old boo off your mind, you need to physically and digitally distance yourself from them ASAP. “Each time we continue to engage or even watch stories or look at pictures on social media, we reinforce the attachment to this person,” says Marcus. That just gives them more space in your head—valuable real estate you need to live your life without them.

9. Your ex is in your dreams

Even if you consciously push the memory of a past relationship out of your mind, it’s still possible for you to wind up dreaming about your ex. “As we sleep, our minds return to the storybooks of our past,” says Dr. Manly. “Memories of our former relationships are less within our control than we might want to believe.”

Waking up to an unwelcome vision of your ex can totally throw you off, leaving you overwhelmed with thoughts of why this is happening and sending you back into the past. And that can blow the impact of an ex-partner totally out of proportion.

The good news is, dreaming about an ex doesn’t necessarily indicate any dissatisfaction with your current life or relationship, says Marcus. It may just be a natural aspect of processing past experiences, she says. So let your brain run its silly little movies at night, but know that in your waking life, you can still be confident in your here and now.

Why can’t I just move on?

Even if a relationship ended on good terms or with total clarity, and there aren’t any unresolved issues, you might still feel like you just can’t move on from your ex. In this case, the experts say one of the below personal characteristics—which have nothing to do with your ex or the relationship—may be the reason you’re feeling emotionally stuck in the past.

1. You’re an overthinker

If you tend to hold onto things, an ex is likely to be no exception. In this case, the reason you can’t forget an ex may be tied to your typical “over-analysis” style of coping, says Dr. Hauser. “Ruminating on a breakup can be a subconscious way to protect yourself from future hurt by attempting to figure out why and how it happened in the first place.”

This can quickly lead you down the road of self-doubt—as analysis of a relationship can only go so far before it turns into self-analysis. In this scenario, you could find yourself wondering if you said something wrong, if you were actually the problem, or if you might just be “not good enough” to warrant your ex’s love, says Dr. Hauser. Any of the above unanswerable questions can let an ex live in your head rent-free.

2. You’ve experienced past trauma that was activated by the breakup

A breakup is bound to linger in your mind and even resurface years later if it hits on preexisting trauma, says Dr. Hauser. One common way this happens is in folks with abandonment trauma, says Dr. Carbino. “If abandonment was present for you psychologically when you were young because of issues with your parents, feeling as if you’re being abandoned again by a partner can really disrupt things for you on a personal and relationship level,” she says.

Instead of being able to move on from the traumatic breakup, you could find yourself “rethinking or reliving the relationship and breakup” in an effort to understand it, says Dr. Hauser.

3. You have an anxious attachment style

People with an anxious attachment style (those who require regular reassurance from a partner) often seek out those with an avoidant attachment style (who tend to push away closeness and vulnerability), by virtue of validating a familiar (if uncomfortable) pattern. But if and when a relationship between people of these two attachment styles dissolves, the anxiously attached person can be left struggling to get the avoidantly attached ex out of their head.

“If you’re anxiously attached, losing a partner is likely an enormous fear and trigger,” says Dr. Hauser. “At the same time, if your ex-partner has an avoidant attachment style, they may appear to be totally over the breakup or have little difficulty cutting off contact, which can just make the breakup even harder for you to process.”

4. You tend to romanticize the past

If you typically wear rose-colored glasses, you could wind up seeing your former relationship in an overly positive light… which may leave you yearning to go back to it. In this mindset, says Marcus, you could conveniently forget all of the ways you and your ex weren’t compatible and only remember that one time when they bought you flowers or cooked you dinner or took you on an incredible trip.

“Romanticizing the past is a nostalgic escape, often triggered by selective memory that emphasizes positive aspects while downplaying negatives.” —Rebecca Marcus, LCSW, psychotherapist

“Romanticizing the past is a nostalgic escape, often triggered by selective memory that emphasizes positive aspects while downplaying negatives,” says Marcus. “This habit can be addictive as it provides temporary comfort and a sense of familiarity—but it also hinders personal growth by idealizing a version of reality that may not align with the full picture.” That’s one reason why you might feel like you can’t get over an ex who treated you badly; you’re just cutting those parts out of your memory.

What can you do if you can’t get over your ex?

Despite the fact that certain realities can keep an ex floating around in your mind, learning to stop thinking about them comes down to the same principles of moving on from any relationship: understanding and accepting your lingering feelings, and creating as much distance as possible through distraction. “Healing from a past relationship involves intentional steps,” says Marcus, and the sooner you begin taking those steps, the sooner you can get that person off your mind.

Allow yourself to process the feelings

“To truly move on, you need to first fully feel your feelings, such as sadness, irritation, and disappointment,” says Dr. Manly. (After all, the emotional stages of a breakup involve acknowledging your feelings first, before you can reflect and accept.) “The more you allow yourself to process your feelings—whether through journaling, talking with friends, or using creative energy to heal—the more likely it is that you’ll move forward quickly.”

Part of that processing might look like doing some introspection about how the relationship panned out and the lessons you can take from it. “Consider what you learned about yourself, what you learned about relationships in general, and what you learned that you do or don’t want in a relationship because of how this particular relationship went,” says Dr. Hauser.

Acknowledge your part in the breakup

It’s easy to get stuck in the trap of blaming a breakup on situational realities like time, location, or the economy, says Dr. Carbino. “These are certainly huge elements that have real effects on dating, but focusing too much on these external factors will keep you from taking a look at yourself and how you might have contributed to the relationship’s pathway,” she says.

By contrast, acknowledging your part (and your ex-partner’s part) in things can keep you from the rabbit hole of unanswerable “what ifs” (e.g., “What if the timing was better?”), which can in turn help you move forward with more agency.

Remember your ex’s negative or incompatible qualities

While you’re processing the relationship, it’s also important to acknowledge the not-so-great qualities of your ex, says Dr. Manly. “It’s natural, if unhelpful, to forget the negative aspects of an ex and get stuck in idealizing and romanticizing,” she says, “but allowing yourself to see the whole picture can make it easier to let go.”

By remembering the reasons why the relationship ended (including the things your partner did wrong and/or the ways in which you weren’t compatible), you’ll also be able to set new intentions for dating going forward, says Marcus.

Reconnect with personal interests

Marcus recommends engaging in activities you are personally passionate about to take your mind off that pesky ex. Practicing self-supportive activities will remind you of the amazing things you’re capable of doing, regardless of your relationship status.

On Dr. Hauser’s personal list of things to do after a breakup? Move your body, dive into work, take a trip, head into nature, and spend time with people who make you laugh and bring you joy.

Cut off contact with your ex

“I always encourage at least a 30-day no-contact period,” says Marcus, of managing a breakup. “Longer is probably better, but I know it can be hard for many to commit to this.” During that period, it’s important to not just avoid texts, calls, and IRL hangs, but also, to cut them out of your social feeds by unfollowing them—yes, really. Getting your ex out of your mind means getting them out of your life (at least temporarily).

Consider counseling

Marcus also suggests seeking therapeutic guidance if it seems like you really can’t get over an ex. Professional support may be especially appropriate if you’re feeling lost about how to move on or dull the emotional triggers surrounding your ex, or you suspect past trauma might be keeping you emotionally stuck. There are plenty of therapists out there suited to support you through lingering feelings for an ex, relationship nostalgia, or unresolved emotions.