Do or do not, there is no try - Yoda
When you think about it there is a lot of truth behind that quote.
Other one I like is:
Contradictions do not exist. Whenever you think you are facing a contradiction, check your premises. You will find that one of them is wrong. - Ayn Rand
But the one that tops it all up was by George Best
I spent 90% of my money on women and drink. The rest I wasted