The other day, I was driving across town, listening to an old Spotify mix, when a song came on that reminded me of a former boyfriend. I immediately drifted into a mental montage of all the great times we had together—beach bike rides, art projects on his kitchen floor, buying the weirdest stuff we could find at the flea market. But my nostalgic haze went *poof* when my mind eventually landed on the defining memory of our relationship: the time I found out he cheated on me.

I know. You might think that’d be the first thing I recall when I think about this particular guy. But, no—I, like so many others, perpetually view my past experiences as happier than they actually were. Once a period of my life is over, it’s like my mind automatically Facetunes it, blurring out any imperfections and bathing it in a hazy, soft-focus glow. The good times stay sharp, while the bad times blur into the background. Admittedly, none of my bad times were that bad to begin with—I’m not talking about serious trauma here, just the regular ups and downs of life. But still, what’s that all about?

The psychology behind seeing memories through rose-colored glasses

According to cognitive behavioral therapist and psychologist Jennifer Guttman, PsyD, there are a few things at play when we romanticize the past. For one, she says, this kind of thinking is a hallmark of a glass-half-full mentality. “Optimistic people tend to have a positive selection-attention bias,” Dr. Guttman says. “That means they selectively choose to assign more focus to positive rather than negative events.”

Furthermore, our brains have to minimize memories so we can store them all, says life coach Katie Sandler. “When we remove details, it’s in our human nature to naturally eliminate the negative aspects before we eliminate the positive ones,” she says. “It’s all about self-preservation.” So when an optimist gets their first job, their mind may weight the fun parts (meeting new friends, spending their first paycheck) more heavily than than the challenging parts (like their nightmare boss). And years later, fun things might pop up first in their mind when they think about that job.

“Optimistic people tend to have a positive selection-attention bias. That means they selectively choose to assign more focus to positive rather than negative events.” — psychologist Jennifer Guttman, PsyD

The other reason many tend to fall into a “good old days” mentality? Doing so makes seeing the world as a safe place easier. “Having positive memories of ‘not-so-great’ life events is a way for us to manage cognitive dissonance,” says Dr. Guttman. “Cognitive dissonance is when we believe that a situation or person should be a certain way, and we receive information to the contrary. When this happens, we make a choice as to which information to retain and which to discard to eliminate the dissonance.”

This mental favoritism can be a positive thing, Dr. Guttman adds. In my situation, remembering the good parts about my doomed relationship is reassuring because it tells me that my ex does have some redeeming qualities, and that makes me feel better about my decision to try and work things out after the infidelity. This is also what helped me to eventually move on, still feeling able to trust my own judgment. “It reinforces our confidence in making decisions about situations and relationships without worrying that our radar is severely damaged,” says Dr. Guttman.

Learning to move forward from the past while still remembering the whole story

If you idealize the past, experts agree you should be extra intentional about learning from your hardships. “Unfortunately, if we don’t remember our painful experiences, we can repeat our missteps, which inhibits personal growth and overall well-being,” says Sandler.

Of course, if you’re dealing with trauma, it’s best to seek help from a mental-health professional. But if you’re just going through a rough patch, Dr. Guttman suggests looking at the situation objectively—whether it’s a friendship break-up, a negative review at work, or money mistakes—and trying to find the lesson in it for next time. “Once you have a roadmap, put it to bed,” she says. “Cleanse yourself of the past and move on, focusing on the present and the positive aspects of life.”

Though it’s for the best to remember the whole story of your past goings-on, being able to tease out helpful takeaways presented by unwelcome life events makes you more resilient, Sandler says. “Rose-colored lenses aren’t the end of the world—romanticizing the past helps us move forward with optimism.” So bring it on, throwback playlists. I’m ready to wax nostalgic, the healthy way.

You’re not imagining it—narcissists do seem like total catches at first, because of these three personality traits. Confusing, right? Well, this nine-step checklist for how to tell if you’ve *actually* found The One can help you clear things up.