When I go home at night and my girlfriend is sat there, the last thing I want to say is "hunny, I'll have to find another job. Super awesome startup-v4 is out of cash, I'll probably have a new job in a month but we'll have to tighten our belts until then."
The question I have to ask myself is this: What's best for my future family? That I 100%, undoubtedly love my job, or that I 100% always put food on the table?
For me it's the latter. For most billionaires, it's probably the former.