Youth is when you're allowed to stay up late on New Year's Eve. Middle age is when you're forced to.
Age is not a particularly interesting subject. Anyone can get old. All you have to do is live long enough.
age, interesting, live long enough
Forty is the old age of youth, fifty is the youth of old age.
forty is old age, fifty is youth of old age
I don't believe one grows older. I think that what happens early on in life is that at a certain age one stands still and stagnates.