Who said "I've learned that growing up is hard."?

This quote is attributed to Bart Simpson.

I've learned that growing up is hard. - Bart Simpson

"I've learned that growing up is hard."

Bart Simpson Change

"Eat my shorts!"

"Ay caramba!"

"Don't have a cow, man."

"Cowabunga!"

"Change brings new opportunities."

"Every day is a new opportunity."

"Healing doesn't mean forgetting."

"You either get better or you get bitter."