Who said "Life's a grind, but you gotta keep spinning."?

This quote is attributed to Bart Simpson.

Life's a grind, but you gotta keep spinning. - Bart Simpson

"Life's a grind, but you gotta keep spinning."

Bart Simpson Perseverance

"Eat my shorts!"

"Ay caramba!"

"Don't have a cow, man."

"Cowabunga!"

"Perseverance is the key to success."

"Don't give up on what you believe in."

"I've been through worse."

"You learn to live with the pain."