It's always too early to quit.
To know oneself, one should assert oneself.
If you've got a talent, protect it.
To be a good loser is to learn how to win.
By failing to prepare, you are preparing to fail.
Expect problems and eat them for breakfast.
If you can dream it, you can do it.
Things do not happen. Things are made to happen.
Begin to be now what you will be hereafter.
Never complain and never explain.
That is a secondary teacher conception - the writer as an observer.