My key takeway on Elon Musk is how much he is willing to bet on something he believes in. Capitalizing SpaceX with $100M when he only had $165M is gutsy. Not saying $65M is chump change, but there is an opportunity cost to putting over half your net worth in one thing. Most people in that position diversify their investments across lots of things, or try to preserve more of it for the future, or are (probably irrational) afraid of losing it and put it aside in a foundation or something.

This is a really good point, and honestly pretty inspirational.

I think the key point is that he wasn't doing it just to make more money, but to do what he always wanted to do (make humanity an interplanetary species). Taking the time to break that huge goal down into steps that can be individually profitable (and thus fuel the next stage) and then executing on them so well is just... awesome.

Your comment inspired me to go hunting for the original SpaceX pitch deck (or similar initial documents). I found one but it's a lot more recent - anyone have a link to the first one?

It's the difference between just wanting to carefully make more money and wanting to do something important. Or to quote Walt Disney "We don't make movies to make money, we make money to make more movies."

I'm not necessarily disagreeing with your point, but having at least one successful exit + being willing to stake $100mil means that other investors are much more likely to sign on.