Golden Birthdays

Tomorrow is my daughter's 14th birthday, and according to her and her brothers, when your age is the same as your birthday, it's called your "golden" birthday. Before my wife and I got married, I had never heard of this concept before, so I was wondering is this something they just made up on their own, or do other people know about this? My wife doesn't know where they got it from either. And unfortunately, I didn't know about it when mine (23rd) came along.