Given the realism of the premise I’d assume they can just go back to sleep and wake up with it all back again.

It depends on the person and how rich. I’ve known a number of people who were multi-millionaires because they were very smart, got jobs doing something they loved that most people couldn’t do well, got paid very well for it, but didn’t spend much money. After some decades of that, it piles up. Those type of people tend to be very down to earth, likable, focus on their families, etc. I can think of a few of those people who, if they woke up with nothing, would be taken care of by their friends and family.

But then there’s billionaire rich. That’s doesn’t come from just making good money and not spending much. It’s hard to believe there’s ever been a billionaire who didn’t get their money through some level of exploitation. So on the one hand, it’s hard to believe they’d have many people feeling sorry for them. On the other hand, ultra rich people tend to have ultra rich friends and family, so I doubt most would fall far.

Call thier bank

Or theyd hatch a scheme to short orange juice futures and put other rich guys out to sail

There was actually a Millionaire named Mike Black that put it to the test. Gave away his company and all his wealth away to family members and chose not to lean on his business contacts or family and “Put it to the test” whether he could rebuild from scratch based entirely on drive and know-how. He quit trying after less than a year because the health consequences of trying nearly killed him.

See, the hard reality is even if you’re giving everything you’ve got to be successful, so are millions of others who are trying just as hard, and the thing that often makes the difference is dumb luck and/or the support of people most wealthy folk don’t even realize people are giving them (sometimes for good reasons, sometimes for less good reasons).

So yes, if you don’t give everything your 110% you’re not going to get anywhere, but giving everything your 110% is probably not going to make you successful. 80% of people who do everything right, fail. Almost 20% just barely hang on, and only the smallest fraction of a percent actually “win”, usually based on factors they don’t even see or acknowledge, and it has nothing to do with talent, brains, or effort.

So if a rich person woke up tomorrow with actually Nothing, it’s possible lightning might strike twice, but more likely, they’d end up desperate, hungry, and homeless just like the rest of us.