I had a bike when I was 12-14 and I lived in the country and rode it a lot by myself and with my friends. I also sometimes rode my brother's 'fancy' Raleigh 10 speed.
After that though, I didn't even so much as sit on a bike until 3 years ago (!!), and I'm now 54 and ride frequently.

I presently live quite near where I used to ride my old bike as a teenager. The other day I rode from the center of that town I used to live in, along a little county highway to an overpass bridge. I remembered doing that ride way back then and thinking it was a huge long adventure with giant hills. Turns out it was NOTHING!- no more than a mile and no hills to speak of at all.
It's like going back to your old school and seeing how tiny the rooms and desks are, where they seemed gigantic in my memory.
I can safely say I can now ride rings around my old young self.