Human variation.

Some people are wired to hoard as much resources as possible, like a squirrel compulsively burying nuts.

We didn't evolve for the abstract concept of wealth we have now. It's just a number on a screen, it can go up indefinitely and at a certain point it's can't help but accumulate.

At a certain point there should be "to much wealth to manage" that limits these people, if they don't have a limit they're never stop hoarding.

If they could have ever been satisfied, they would have been long before a billion.

What I don't get is why not everyone see this....