Who said "I have learned that change is the only constant."?

This quote is attributed to Thor (Age of Ultron).

I have learned that change is the only constant. - Thor (Age of Ultron)

"I have learned that change is the only constant."

Thor (Age of Ultron) Change

"I am mighty, but I am not all-powerful. This is a lesson I continue to learn."

"A warrior's strength comes not just from muscles, but from the heart that drives them."

"We are stronger together than we could ever be apart."

"The best of us must sometimes make the hardest choices."

"Change brings new opportunities."

"Every day is a new opportunity."

"Healing doesn't mean forgetting."

"You either get better or you get bitter."