Who said "Gratitude for what we have is the key to true happiness."?

This quote is attributed to Sylvester the Cat.

Gratitude for what we have is the key to true happiness. - Sylvester the Cat

"Gratitude for what we have is the key to true happiness."

Sylvester the Cat Gratitude

"Sufferin' succotash! That's not how you catch a puddy tat!"

"A cat's life is what you make of it - mostly chasing and scheming."

"Love makes you do crazy things, like chase a bird for decades."

"The secret to happiness is never giving up, no matter how many times you fail."

"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"