Money

Goddam money. It always ends up making you blue as hell.

— Young people, nowadays, imagine that money is everything.
— ...and when they grow older they know it.

It took money to be a lady.

"Yes, I want money more than anything else in the world."
"Then you've made the only choice. But there's a penalty attached, as there is to most things you want. It's loneliness."

It was all very careless and confused.
They were careless peoples, Tom and Daisy—they smashed up things and creatures and then retreated back into their money or their vast carelessness, or whatever it was that kept them together, and let other people clean up the mess they had made…

"Do I mean so much to you?"
"Well, yes. You see, I've invested a good deal of money in you, and I'd hate to lose it."