First of all, he never actually said that he invested money he couldn't afford to lose. Moreover, as he mentioned, he believed that even a complete loss was something he could potentially recover from given his age at the time. That's a really crucial point to consider.

But yeah, you're right, the thought of just sticking it out through all those Bitcoin drops over the past 11 years blows my mind and  watching your money basically evaporate like that, over and over, takes some really serious belief particularly when it's a big chunk of what you've got.  I mean, seeing 80 or 90 percent of your money go poof has gotta take some real nerves of steel. Most people probably would've tapped out way before that.