Growing up, onset of puberty, early youth (12 - 24).
After returning back to the country, I was enrolled into an old red-brick building school with strict rules. One boy in my class payed quite a bit of strange attention to me, often in a naughty or disruptive manner. I ignored him for a long while, but something in his daring persistence appealed to me, as well as his exceptionally good looks. We started talking, and then going for long walks by a river.
My parents had many friends - geologists, philosophers, mathematicians, and many others, but mostly from academia - and we often partied at our place and their homes.
Their kid's minds, including mine, were routinely challenged with philosophical paradoxes, barely conceivable facts, and existential problems.