Who said "I think deep down you're a really good friend."?

This quote is attributed to Billy.

I think deep down you're a really good friend. - Billy

"I think deep down you're a really good friend."

Billy Friendship

"I'm a big fan of science!"

"Mandy, wouldn't it be great if we could stay young forever?"

"I love the smell of destruction in the morning!"

"Why does everything have to be so complicated?"

"Friendship is built on trust and honesty."

"True friendship is worth more than gold."

"Good friends are like stars, always there even when you can't see them."

"Friendship means sacrifice."