Who said "Oh boy, motivation comes from believing in yourself."?

This quote is attributed to Mickey Mouse.

Oh boy, motivation comes from believing in yourself. - Mickey Mouse

"Oh boy, motivation comes from believing in yourself."

Mickey Mouse Motivation

"Hot dog!"

"Oh boy!"

"Gosh!"

"That's swell!"

"I believe in working hard for what you want."

"Never underestimate the power of determination."

"I don't need a reason to fight."

"The most important thing is the mission. Nothing else matters."