"The mediocre teacher tells. The good teacher explains. The superior teacher demonstrates. The great teacher inspires."
- William Arthur Ward.

"Everybody who is incapable of learning has taken to teaching."
- Oscar Wilde

"What I hear, I forget.
What I see, I remember.
What I do, I understand."
- Confucius

"I have never let my schooling interfere with my education."
- Mark Twain

"Before you become too entranced with gorgeous gadgets and mesmerizing video displays, let me remind you that information is not knowledge, knowledge is not wisdom, and wisdom is not foresight. Each grows out of the other, and we need them all."
- Arthur C. Clarke

"Cogito, ergo sum." (I think, therefore I am.)
- Descartes

“Good teaching is one-fourth preparation and three-fourths pure theatre."
- Gail Godwin

"There are two types of education... One should teach us how to make a living, And the other how to live." John Adams

"What sculpture is to a block of marble, education is to a human soul."
- Joseph Addison

" The paradox of education is precisely this-- that as one begins to become conscious one begins to examine the society in which he is being educated."
- James Baldwin

"He who dares to teach must never cease to learn."
- Richard Henry Dann

“Apply yourself. Get all the education you can, but then...do something. Don't just stand there, make it happen."
- Lee Iacocca

"Education is not the filling of a pail, but the lighting of a fire."
- William Butler Yeats

And my brother's favourite, which he says works for all occasions:

"A dog is a man's best friend." - my brother