Never consider yourself too mature to act childlike.
We never grow up, we merely become “wrinkled kids.”
With that in mind, kids don’t want to work all the time. Kids don’t like responsibilities. Kids like to play.
If we don’t engage in some time where we aren’t “on,” we squelch a vital part of who we are. That makes us inefficient, overwhelmed, and — of course — sad. (Besides, who wants a life of solid responsibilities anyway?)