Youth is a loan, not a gift. Use it on something that pays you back.

Energy, time and the freedom to fail are all in unusual supply early on, and all three are temporary. Treating them as permanent is the natural mistake, since nothing about having them suggests they are being counted. Some ways of spending them return something and some simply pass.

That does not mean every hour has to be productive, because rest and pointless fun both pay back in their own way. It means noticing what gives nothing at all, and moving a little of that time towards learning, making or people. Small reallocations are enough.