You left out the most significant reason: that most people just aren't as lucky as those guys. In the US, you can become a millionaire through hard work and de

You left out the most significant reason: that most people just aren't as lucky as those guys. In the US, you can become a millionaire through hard work and dedication and not much luck. However, there is nowhere that you can become a billionaire without tremendous luck. Amassing that type of wealth depends on many other people embracing your ideas, and random events that are entirely beyond your control working out in your favor. There are ways to improve your odds of reaching this level of success - if you never start a business, your odds are zero. But luck is the ultimate decider of who becomes a "self-made" billionaire out of those that are actively trying to become one.