The more I learn about finance, and the better I grok money, the more I start to think of money as a substance that represents time-travel, in a sense. Current amount of money you have on your account is always tied up to your past decisions or to a space of your possible decisions about it, and so well-quantified, that the worth of basically anything is always tied up to a dynamic process which is always, in the end, measured in time.
(OK, I just understood that what I wrote reads as a horrible unintelligible mess, but I didn't yet grok this idea well enough to put it down elegantly.)
Also a bet that you will live to later. I've known a few people who died young: on hindsight they should have lived life better and not saved so much (I have no idea how much they saved, but even 1 penny in their pocket...)
(OK, I just understood that what I wrote reads as a horrible unintelligible mess, but I didn't yet grok this idea well enough to put it down elegantly.)