Answer:
getting old
Step-by-step explanation:
Juan Ponce de Leon was a Spanish conqueror who overwhelmed and claimed for the crown the island of Puerto Rico in 1508 and went on several other military expeditions.
He was afraid of getting old because he was rumored to have searched for the mythical "Fountain of Youth" in which any that bathes in its waters would regain their youth. Unfortunately for him, he did not find it.