For my first job in high school, I worked as a lifeguard at the local civic center swimming pool. Beyond the easy pool access, extra spending money, and killer tan, I have to admit that I really enjoyed the weird smells of fresh chlorine in the morning.

The smell of chlorine is a weird thing to enjoy. Chlorine can be incredibly toxic to humans; breathing it in large doses can lead to pulmonary edema. Its chemical properties are so strong that it can turn blonde hair green and strip skin of its natural oils, and yet, I crave the smell of it every year when springtime hits.

An appreciation of weird smells seems to be a universal experience. Cow manure, fresh tennis balls, gasoline, and even the bottom of dogs’ feet (Fritos, anyone?) are just a few of the strange smells people say they can’t get enough of. Where does our affinity for strange, sometimes noxious, smells come from? Does the nose know something we don’t?

Why do you love weird smells so much?

Before we tackle why we love strange smells, it’s important to understand the relationship between smells and the human brain. When scents travel up our nose, they eventually hit the olfactory nerve, located in a small patch of tissue high up in the nasal cavity. This nerve houses receptors that detect scent molecules and relay that information to the olfactory bulb in the brain. This bulb is part of our brain’s limbic system, the part of our brain that controls memory formation and recall.

Memory

If you love a specific strange smell, there’s a strong possibility that it’s directly tied to your memory. According to Mandy Naglich, beer taste expert and author of How to Taste: A Guide to Discovering Flavor and Savoring Life, says that odor, much like taste, has the ability evoke long-term autobiographical memories in a way that the other senses cannot. Studies have shown that recalling a fond memory can put you in a good mood, so if you have pleasant memories of playing tennis with your family as a kid, you’re more likely to enjoy the smell of tennis balls.

“Scientists think these parts of the brain [limbic system] are responsible for assigning emotional meaning to events,” says Naglich. “Hence, by their nature autobiographical memories triggered by scent must also trigger an emotion. Rather than being simultaneous recollections, emotion and memory are inherently intertwined as one.”

It’s in your genes

Humans are wildly diverse when it comes to our scent likes and dislikes. Each of us have approximately 400 odorant receptors, and any two people are likely to have a 30 percent difference in odor reception function between them. Our sense of smell is unique and wholly ours, which could explain why some people love the sawdust-y smell of Home Depot while others don’t seem to notice it at all.

Context

While you might love the smell of gasoline on a chilly winter evening or the smell of skunk during a cross-country road trip, you probably don’t want to smell them in your own home. This is because the context of smells is paramount to whether we like them or not in the moment. Since olfaction is directly linked to our memory, we’re more likely to have a positive reaction to smelling them in the context where we formed good memories.

Common Weird Smells and Why You Like Them

Gasoline

The sweet odor of benzene, a chemical solvent found in crude oil, could be responsible for our collective obsession with the smell of gasoline. Cigarettes and fires also contain trace amounts of the aromatic compound, which could explain why the smell of bonfires and tobacco are so popular, even amongst nonsmokers.

Our love for the smell of weird smells, especially gasoline, is so widely-shared that luxury perfume brands like Snif have begun using them as inspiration for new fragrances. Known for their experimental, “out there” scents, Snif formulated a fragrance for their secret NoNoses menu called Dead Dino that contains a scent profile built around the strong smell of petrol.

“We wanted our first scent to evoke some form of nostalgia, and when we polled our community, the smell of gasoline kept coming up, and that’s how Dead Dino was born,” says Phil Riportella, co-founder of Snif. “It’s really the memories associated with those nostalgic scents that make it so interesting.”

Snif, Dead Dinosaur — $65.00

Chlorine

This one’s a little gross. The strong smell of pool chlorine is due to chloramines, volatile substances that form in pool water when chlorine bonds to water contaminants like sweat and pee (ew). Speaking from experience, raw chlorine powder and pellets do smell very strong, but you’re likely smelling the water’s chloramines, since chlorine is kept in airtight containers hidden in the pool’s maintenance room.

As with all weird smells, context is important, and our love of pool smell is strongly linked to childhood memories of swimming with family and friends.

Your partner’s armpits

If you find yourself savoring the smell of your boyfriend’s armpits, you’re not alone. The explanation for this is actually pretty romantic. For one, your partner’s body odor can bring you a sense of comfort or arousal; smells linger, so when you get a whiff of their dirty t-shirt, you’re reminded of them.

Secondly, scientists theorize that our unique major histocompatibility complexes (MHC), collections of genes that code for proteins that help our immune systems, can dictate our biological attraction with potential romantic partners. One study involved asking women to rank the pleasantness of body odor from six different shirts, all worn by different men for two consecutive days. The group ended up preferring the smell of shirts from men whose MHC makeups were different from their own, suggesting that opposites *do* attract.

The Nose Knows

If you still think it’s nasty that some of us like the smell of skunk, we get it. Despite how *gross* they may be, the powerful scents of chlorine, skunk, gasoline, and sweaty armpits have the power to transport us back in time. The magnificent teamwork between our olfactory systems and our brains—an intricate pairing wholly unique to each and every one of us—is nothing to sneeze at.