My impulse was to post something about Scrooge McDuck and a deep-seated satisfaction that can only be obtained by swimming in a giant room full of gold coins... however...

Seriously, another possible motivation is, quite frankly, to beat someone else. As, for example, the Richard Greer character in Pretty Woman, whose original motivation was simply to punish his father by taking over his company and destroying him.

...
Regards,
Eric Fretheim