As you know, Growing Up Sucks. Some children, however, have found a way to halt their aging at childhood via Applied Phlebotinum or some supernatural means. Most of the time they'll have the mind, emotional maturity, and/or sensibilities of a child as well as a prepubescent body; adults in children's bodies are more likely to find it inconvenient or downright sucky, although not always. Compare Not Allowed to Grow Up and Really Seven Hundred Years Old. Not to be confused with Adult Child. When the same effect causes hardship and angst for the eternal child, it's Not Growing Up Sucks.