Who said "It's not fair! It's just not fair!"?

This quote is attributed to Charlie Brown.

It's not fair! It's just not fair! - Charlie Brown

"It's not fair! It's just not fair!"

Charlie Brown Justice

"Good grief!"

"I got a rock."

"Rats! I did it again."

"Why is it that everything I do turns into a disaster?"

"Justice must always prevail."

"You think I'm just some animal?"

"Fighting for what's right never gets easier."

"Justice is worth fighting for."