Who said "I'm not supposed to be here, but I am."?

This quote is attributed to SpongeBob SquarePants.

I'm not supposed to be here, but I am. - SpongeBob SquarePants

"I'm not supposed to be here, but I am."

SpongeBob SquarePants Courage

"I'm ready!"

"Ahahaha! I love you."

"The best time to wear a striped sweater is all the time."

"I'm a goofy goober, yeah!"

"Never let fear stop you from chasing your dreams."

"Courage is being afraid but doing it anyway."

"Sometimes you gotta do what you gotta do."

"Sometimes you have to be the monster to stop the monsters."