Lots of people have one skill, few people have two, and only a tiny fraction ever put multiple skills to use at once.
He also adds that it easier to do this (combining two or more skills) than it is to be the very best at one thing e.g. an NBA player--it is actually easier, statistically, to become a billionaire than it is to become an NBA player.
There are more than 2,000 billionaires worldwide but only about 480 NBA players (32 teams with roughly 15 people on the roster). And if you think about it, becoming a billionaire usually involves multiple skills (good at programming + business, bill gates. Good at research/analysis + cultivating a rare temperament that allows you to act on the insights produced by the research even when everyone around you is losing their shirt, Warren Buffett etc, etc).
Being an NBA player requires one skill at a minimum. Being tall!
That's not really true. Once you are billionaire you can stay a billionaire for decades. Meanwhile most NBA players don't have long careers, many stay in the league only for a few years. I'd expect that over 10-20 years there have been more NBA players than billionaires.
Being an nba player involves luck and hard work and a high spacial iq.
Anyone could become a billiarie with luck (powerball lottery in one extreme). Only 100,000 people in the world would even have a chance to compete to be an nba player.
Most billionaires were born in top 0.01 percentile of their respective population pool. And had to be lucky and smart amongst other traits.
Muggsy would disagree ;)