Certain special aromas can trigger flashbacks to past experiences.

Falling in love, bowling a strike, catching a subway just as the doors are closing – life affords us many emotional peaks. But surely one of the Top 10 must involve opening a can of Play-Doh.

Oh, the memories one whiff can release! Wham – there you are, rolling out long, lumpy snakes and mashing them into the rug. There’s absolutely nothing more intoxicating than Play-Doh except, maybe, the smell of rain.

Or dirt. Or paste. Or those big, bouncy red rubber balls.

This summer, as we breathe deep the bus fumes, blossoms, bug spray and sweat, let’s hear it for our noses’ amazing ability to rocket us back to the past.

“It’s not something that people talk about very much,” says Theresa White, an assistant psychology professor at Le Moyne College in Syracuse, N.Y. “But when you bring it up at a party, everyone will give you a zillion examples.”

It’s true. Smell is usually undiscussed because so many smells are considered rude – as is noticing them at all. But even the ickiest, stickiest stench – think old gym uniforms – can unspool memories you didn’t realize you had saved. Suddenly, you are back in high school gym class.

And just as suddenly, you are back in therapy. But anyway – how does this phenomenon happen?

“Smell is very ancient,” says Dr. Charles Kimmelman, a smell and taste expert at the Manhattan Ear, Nose and Throat Hospital. Before organisms had eyes or ears, they had a sense of chemical awareness – what we now call taste and smell. Through this awareness, they sensed danger, food and fellow organisms to spawn with. In other words: Smell kept them alive.

Throughout evolution, smell kept its special status. Even today, our nose nerves go directly into that vital part of the brain where we process both short-term memory and emotion. That’s how smell, memory and emotion ended up bundled together.

Our sense of smell also happens to be keenest when we’re young, and even keener in the summer, which is why so many smells – Baskin-Robbins, bathing caps – bring

back summer vacation.

Another reason smells pack such a wallop is that advertisers have not yet figured out a way to exploit them, the way they have with songs. Odds are, whatever youthful anthem was blaring at your prom, it is now the soundtrack to a car commercial. No longer is it linked to a single time and place. But the smell of your prom date’s perfume – a scent that no one older than 16 wears for fear of smelling like a raccoon in heat – remains in your memory, powerful. Waiting.

And then it hits.

Doug Greenberg, a thirtysomething Manhattanite, works above a peddler selling incense on the street. Each day, the peddler lights a different scent, and each day, Greenberg finds himself flashing back to his high school bedroom, where he, too, used to burn incense.

“Depending on the flavor,” he says, “I can remember specific music that was playing on the radio, even specific conversations on the phone.” Thanks to his nose, he time-travels every day.

Another friend of mine also named Doug (sorry – common name) broke up with his first love 29 years ago. But one hit of Herbal Essence shampoo, and he’s google-eyed again. “If I smell it today, a tear can come to my eye.”

Well, a tear almost came to my own eye the other day as I passed a car wash and that sudsy, funky smell somehow brought back summer. Come to think of it, so did the smell of the plums I bought. And the flip-flops! God, everything is bringing back those sweet summers of long ago.

And some day our kids will smell Kool-Aid, Off or sunscreen and shed a tear for today.

Lenore Skenazy is a columnist for the New York Daily News.