Haha I'm pretty sure that qualifies as exercise too.

Leg strength seems harder to maintain. That was always one of my weak points. I used to be able to do chin-ups and dips all day but if I tried to do squats, I'd be soaked in sweat and out of breath from what should require very little effort.

I think you're onto something there. Maybe we learn not how to burn ourselves so fast or maybe it comes from the years of conditioning that we get from working and doing all those things adults are supposed to do.