Now I had been 2 of these 3 things and I'm seeing the third one a round me.
Definitely will say number 1 - Childhood !
Imagine this: You are kid, its summer, the only responsibility you have is to not miss the cartoon show at 15:00. You are running, playing, raiding a bike, playing with your friends hide and seek until nightfall even late, building three houses and keeping secrets from your parents just to not get punished.

It was amazing and there were no worries like now - money,food,rent,car,wife,how to get thru the month and live until the next one..