Who said "I don't think I can do this."?

This quote is attributed to Bart Simpson.

I don't think I can do this. - Bart Simpson

"I don't think I can do this."

Bart Simpson Fear

"Eat my shorts!"

"Ay caramba!"

"Don't have a cow, man."

"Cowabunga!"

"Face your fears with courage."

"You can't live your life in fear."

"Snakes. Why'd it have to be snakes?"

"Fear is just another obstacle to overcome."