Bill Gates also came from a millionaire-or-richer family, so that'd make 4, if that's the cutoff you're using. (He inherited several million from his grandfather, in a generation-skipping trust fund, although I don't believe he yet had access to that money at the time of founding Microsoft.)
Yeah, my logic was that he didn't have/use those resources while building Microsoft. I was trying to divide billionaires into those who built up their wealth without relying much on other resources, vs. those who took existing wealth and grew it.
