Regardless of whether your first kiss was a melee of brace clashing or living out your every Mills and Boon fantasy, you probably remember yours.
Even once the first kiss is done and dusted, kissing anyone new at whatever age can be a minefield.
Kissing someone for the first time may seem like Russian roulette and is not always guaranteed to be enjoyable, but there's a lot more going on behind the scenes than you may realise.
At least, if it's a good kiss.
"Kissing is an instinct which aims at releasing chemicals in order to experience pleasant feelings," Takeesha Roland-Jenkins, a professional consultant for the Between Us Clinic , says.
"Furthermore," she adds, "the lips have nerve endings that become stimulated upon kissing, leading to the activation of additional senses such as smell."
Here are five other fascinating things which happen when you kiss someone for the first time.
1. You de-stress
In times of stress you may prefer to have a nice, stiff drink - but you may want to re-think that strategy, especially if you're male.
A study cited on NBC found college students who participated in 15-minute kissing sessions managed to dramatically decrease their levels of the stress hormone cortisol.
Not only this, but male participants also experienced a rise in oxytocin, the brain’s feel-good chemical.
Sadly, females actually saw a decrease.
2. It helps fight cholesterol
If you're looking for a reason to bin those cardio sessions, look no further: kissing can have a positive impact on your blood lipid levels.
Researchers for the Western Journal of Communication found, that romantic kissing can actually decrease serum cholesterol and increase overall relationship satisfaction for couples.
3. Your saliva is VERY clever
You've probably not given your slobber much thought, but you may owe your choice of partner to it.
Sloppy kisses are working hard to assess if the person you're kissing is a potential mate, according to research conducted by Oxford University .
Apparently, the chemical makeup of saliva helps your body decide if the person you’re kissing would produce strong offspring.
Which is more than we gave it credit for, to be fair.
4. You experience an adrenaline rush
A 'fight or flight' chemical, when we kiss someone for the first time, our bodies will release a burst of adrenaline which increases our heart rate, boosts our energy levels and gets the blood flowing.
All of which are good things.
5. There are plenty of happy chemicals produced too
A whole raft of other chemicals come flooding in too, making us feel pretty chipper.
Justin Lehmiller, a Harvard professor of psychology says that when we kiss, our brains are flooded with dopamine.
Dopamine is the very same chemical that is released when we do other stuff we enjoy a lot.
Quite a nice shock, isn't it?