Who said "Your greatest teacher may be your fiercest opponent."?

This quote is attributed to Stick.

Your greatest teacher may be your fiercest opponent. - Stick

"Your greatest teacher may be your fiercest opponent."

Stick Education

"A man without sight sees more than most men with eyes."

"Your blindness is not a weakness. It is a gift."

"The mind is sharper than the blade."

"Fear is the enemy of progress."

"Education opens doors."

"Education opens doors to endless possibilities."

"I ain't got the education you got, bub."

"You can't put a price on history."