Who said "Gratitude is the most powerful tool we have."?

This quote is attributed to Mario.

Gratitude is the most powerful tool we have. - Mario

"Gratitude is the most powerful tool we have."

Mario Gratitude

"It's-a me, Mario!"

"Let's-a-go!"

"Mamma mia!"

"I'm not giving up on my brother."

"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"