The reverse of Fountain of Youth, this is a scenario where Applied Phlebotinum (frequently in the form of a wish) turns one or more children into adults. Hilarity Ensues, and the kids either fumble around awkwardly in their post-pubescent bodies, or learn An Aesop about adult responsibilities and/or not being in too big a hurry to grow up. Can also include a young adult character or one in early middle age becoming elderly. Not to be confused with Plot-Relevant Age-Up or Soap Opera Rapid Aging Syndrome. Sometimes combined with Older Alter Ego or She Is All Grown Up.