A humorous saying for a 50th birthday is, "If you haven't grown up by age 50, you don't have to." Another funny saying is, "At 50 years old, life seems shorter. No point in spending it trying to make yourself disappear by dieting."
Some 50th birthday sayings focus on the difficulties and annoyances upon reaching this age. For example, one tongue-in-cheek quote is, "You spend more time trimming your nose hair than head hair." Another quote talks about the wisdom gained with age: "You realize with some irritation that your parents were right about nearly everything."
While 50 is considered old enough to acquire wisdom and maturity, some humorous quotes focus on the fact that 50-year-olds have not necessarily matured. One allusion to this tendency is the saying, "I'm aiming by the time I'm 50 to stop being an adolescent."
Other funny quotes focus on the health challenges of being a 50-year-old. "At 50, you've entered the stone age: gall, kidney and bladder," one quote states. Other funny quotes focus on women as they go through menopause, such as, "You're still hot, but only in flashes," or, "50 is a powerful age for women. You can set off sprinkler systems with your hot flashes."