Who said "Never give up, unless it's hard."?

This quote is attributed to Cartman.

Never give up, unless it's hard. - Cartman

"Never give up, unless it's hard."

Cartman Perseverance

"Screw you guys, I'm going home!"

"I'm not fat, I'm just big-boned!"

"You will respect my authority!"

"Hippies, they're everywhere!"

"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."