Who said "I believe in the power of positive thinking."?

This quote is attributed to Rex.

I believe in the power of positive thinking. - Rex

"I believe in the power of positive thinking."

Rex Motivation

"I'm a dinosaur! RAWR!"

"Oh no, oh no, oh no, oh no, oh no!"

"I can't take the pressure!"

"Everything's gonna be okay, right?"

"I believe in working hard for what you want."

"Never underestimate the power of determination."

"I don't need a reason to fight."

"The most important thing is the mission. Nothing else matters."