It's like Fifteen, but with more peeing

I'm on a mailing list with fellow 3D artists, some of whom are in their 40's and beyond. I, at 31, am one of the youngest of the group. Today, one of our compatriots turned the Big 4-0. One of the fellow youngsters on the board said, "Whats this 40 you speak of?" and asked me if I knew. I opined: "Seems to be a mythical creature that makes you angry, have to pee a lot, and imbues you with the sense that you know everything. It's kinda like "fifteen", but with more peeing." Seems pretty astute to me, but I guess I'll find out for sure in 9 years.