Who said "You know, I never thought I could do that, but I did."?

This quote is attributed to Butters Stotch.

You know, I never thought I could do that, but I did. - Butters Stotch

"You know, I never thought I could do that, but I did."

Butters Stotch Motivation

"I'm not bad, I'm just drawn that way"

"Aw, hamburgers!"

"You're grounded, mister!"

"I have to go do my chores now"

"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."