A person who possesses "eternal youth"; "Peter Pan syndrome"; eternal boy: Old Uncle Tom was a puer aeternus because he still seemed to have feelings and emotions like an adolescent boy!

Translation: "An old man is a boy again" or "old age is considered a second childhood for some elderly men": The grandchildren of the old man kept him so busy that he told his daughter-in-law that he really understood what the Latin expression Senex bis puer means because he was so involved with the children.