It's always too early to quit.
Well done is better than well said.
If you've got a talent, protect it.
To be a good loser is to learn how to win.
You never know what motivates you.
Expect problems and eat them for breakfast.
Never complain and never explain.
If you think you can do it, you can.
The dog that trots about finds a bone.
The wise does at once what the fool does at last.
If you decide to design your own language, there are thousands of sort of amateur language designer pitfalls.