Big John, Little John | 1976
While vacationing in Florida, John Martin -- a science teacher at Madison Junior High School -- and his family visit the Ponce de Leon National Park. While exploring, John finds a small spring -- the mythical Fountain of Youth sought by the Spanish explorer -- and drinks from it. Some weeks later the effects become evident. The middle-aged Big John reverts unpredictably to the twelve-year-old Little John, and vice versa. Stories depict Martin's struggles to cope with his embarrassing condition and his attempts to find an antidote.