If you've got a talent, protect it.
Know or listen to those who know.
Never complain and never explain.
Things do not happen. Things are made to happen.
It's always too early to quit.
You never know what motivates you.
Problems are not stop signs, they are guidelines.
Begin to be now what you will be hereafter.
The wise does at once what the fool does at last.
Expect problems and eat them for breakfast.
If you decide to design your own language, there are thousands of sort of amateur language designer pitfalls.