Who said "Wisdom is not the privilege of the old alone."?

This quote is attributed to Gandalf.

Wisdom is not the privilege of the old alone. - Gandalf

"Wisdom is not the privilege of the old alone."

Gandalf Knowledge

"All we have to decide is what to do with the time that is given us."

"Even the smallest person can change the course of the future."

"There is some good in this world, and it's worth fighting for."

"A wizard is never late, nor is he early. He arrives precisely when he means to."

"We're not just after treasure. We're preserving history."

"The mind is humanity's greatest tool."

"A tidy room reflects a tidy mind."

"You can learn a lot about a person by how they keep their space."