Be gentle to all and stern with yourself.
Always desire to learn something useful.
Be kind whenever possible. It is always possible.
Quality is not an act, it is a habit.
It's always too early to quit.
What you do today can improve all your tomorrows.
If you can dream it, you can do it.
Know or listen to those who know.
Well done is better than well said.
If you've got a talent, protect it.
That is a secondary teacher conception - the writer as an observer.