For some of us who are in 20~30, I recommend Sam Altman's "The days are long but the decades are short"[0].
[0]: http://blog.samaltman.com/the-days-are-long-but-the-decades-...
[0]: http://blog.samaltman.com/the-days-are-long-but-the-decades-...
Definitely a 20-30 thing, never even crossed my mind before I was 25.
Typo - "Shot" should be "short"
Although I have to admit, that word might fit in some cases...