What Makes an Investor Successful?

Patience.
"Don't invest when you have ants in your pants."
-HJC
People don't become rich by chance. They become rich by patience and discipline. They work the same as anybody else, but they spend and live different. They often become rich by biding their time 'till the right opportunity comes along. They save as much as they can, and when the right opportunity comes along they have a chance at it!