I disagree. I believe that a big reason kids are so good at learning and trying things is that they haven't yet internalized the concept of "not enough time" - there's always shitloads of time; if not today, then tomorrow. If not this summer, then next summer. When you don't have to worry about running out of time, you don't mind blowing it on learning stuff.

There's the rub. The feeling of "There's just not enough time." precisely stems from the fact that our time is limited. If that's no longer given that feeling might disappear from humanity entirely, which in turn could lead to stagnation and ultimately - and ironically - to mankind dying out.