Who said "I'm grateful for Mandy, even when she's mean."?

This quote is attributed to Billy.

I'm grateful for Mandy, even when she's mean. - Billy

"I'm grateful for Mandy, even when she's mean."

Billy Gratitude

"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?"

"Gratitude makes life richer."

"A grateful heart is a happy heart."

"Respect those who came before us."

"Life's greatest treasures are the people we love"