Who said "I've learned that gratitude is the best attitude."?

This quote is attributed to Luigi.

I've learned that gratitude is the best attitude. - Luigi

"I've learned that gratitude is the best attitude."

Luigi Gratitude

"It's-a me, Luigi!"

"Mamma mia!"

"Let's-a-go!"

"I'm-a scared, but I'm-a going anyway!"

"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"