George Santayana said this quote

“ Never have I enjoyed youth so thoroughly as I have in my old age. In writing Dialogues in Limbo The Last Puritan and now all these descriptions of the friends of my youth and the young friends of my middle age I have drunk the pleasure of life more pure more joyful than it ever was when mingled with all the hidden anxieties and little annoyances of actual living. Nothing is inherently and invincibly young except spirit. And spirit can enter a human being perhaps better in the quiet of old age and dwell there more undisturbed than in the turmoil of adventure. ”