“I can’t doesn’t exist.” That’s what I learned from Mamie McCullough. As a former public school teacher and principle, Mamie heard “I can’t” frequently. “I can’t get my homework done.” “I can’t finish my paper.” “I CAN’T DO IT!” Sound familiar? Anyone with teenagers knows the familiar litany. Apparently, Mamie was equally frustrated and set out to prove “I can’t” doesn’t exist and “I can” does.