i tend to see most success stories as luck of the draw. don't know anything really about sam's journey other than what is here, so can't say i know his specific story, and don't really care.
a super-rich dude might need to work hard, or not, but your born circumstances largely predict your success, imo, as seems to be pointed out by science/stats.
but i figure the key ingredients to getting rich, esp without accomplishing 'much' in a traditional sense, are:
* born in america, or able to get there at some point
* not poor, higher level incomes/professions/entrepreneur parents better
* white
* male
after that, you've got a real good chance of BIG FINANCIAL SUCCESS, if that's your thing.
add Stanford, and now you're virtually guaranteed big/huge financial success -- the only question now is how successful/rich do you want to be, and how quickly?
just my take.
i just feel like OP was probably looking for a "BUT WHAT DID HE _DO_??"-type of explanation, and i'm like, well, did he meet the prerequisites -- i.e. what were the circumstances of his birth/upbringing? if so, he was born in the top 1% of the top 1% of the global population -- that's a pretty good start.
i don't know anything about Sam's particular situation other than what comments said here.
i do enjoy learning about people who fail upwards or just do really well after having not done much -- you can see if it fits into your worldview, and if not, learn and change your worldview.
ditto the stories of the lower-class-born people who make it big - someone maybe like Mark Cuban (or sam altman? no idea of his bg).