IMO, you don't have to directly inherit a large sum of cash or assets to disqualify you from being considered self-made. People consider Bill Gates to be self-made because he founded Microsoft, but his father was a prominent lawyer and his mother was on the board of directors for a bank and the United Way. His parents were already millionaires with connections. Bill was already very likely to be successful.
Doing a quick bit of estimating, if his parents were worth $10MM USD, and he reached $100billion in net worth, then he increased their wealth 10,000 times. Note that it is not yet inherited, as he achieved that wealth while both parents were alive.
I'd surmise that anyone that increases their wealth 10,000 times more than their parents is self made.
If Bill's parents only had $100, and he reached a million (10,000 times higher), then he'd still be "self-made".
To me at least, anyone who increases that much is impressive, regardless of what they started with - it's the multiple that is key.
So I guess the question is what is the probability of the child of a multimillionaire increasing their wealth by 10,000 times?
It's a lot easier to turn $10M into $100B than it is to turn $100 into $1M.
With $10M, you already have the basics handled. You can have a house and car that are paid off and enough cash stashed away to handle living expenses for the rest of your life and still have $7M+ to piss away. If you're smart and never dip into the funds reserved for lifetime living expenses, it's impossible to fail.
With only $100, you're struggling to put food on the table. Possibly even working two jobs with no time to work on building a business.
And here, I haven't even touched on the concept of "connections". Someone with an 8-figure bank account likely knows who to talk to when it comes to getting a product in front of the right people.
If Bill's parents had only $100 and turned it into $1M, then definitely, he'd be self-made. But since he started with likely an 8-figure backing, he's definitely not.
Baloney! If it were, there would be tons of people with Bill Gates level wealth! (last I checked, there were only 2 - him and Bezos).
The facts speak for themselves.
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EDIT:
After rereading this comment, the tone I have ("Baloney!") seems harsher than Iintended. Still, I'll leave it as such because I don't like to change what I wrote on HN. Please don't take it as an insult, but rather as emphasis of the extent that I disagree with your point.
But even if we tone it down by an order of magnitude or even two, I think it still applies. I think turning $10M into $1B is easier than turning $100 into $10,000, for the same reasons outlined above. Don't underestimate the massive impact it has to be starting at a level where living expenses are of zero concern.
You're only stuck in a $100 asset hole if you refuse to do anything about it, or if you intrinsically offer no value to the world.
Highly doubtful - I'll look it up later and do a mea-culpa if I'm wrong, but if his parents gave him $10+ million in the mid 1970's, I'll eat my hat.
Rich people have many more opportunities to get richer, than any of the rest of us.
Answer - because it's really freaking hard to multiply by 10,000 times.