Well, it's not a mid-life crisis, but here's how things worked out for me.
Married 48 years, took a look at my wife one day and said, "Honey, 48 years ago, we had a cheap apartment, a cheap car, slept on a sofa bed and watched a 10 inch black and white TV, but I got to sleep every night with a hot 22 year old blond. Now, we have a nice house, nice car, big bed and plasma screen TV, but I'm sleeping with a 70 year old woman. It seems to me that you are not holding up your side of things."
My wife is a very reasonable woman.
She told me to go out and find a hot 22 year old blond, and she would make sure that I would once again be living in a cheap apartment, driving a cheap car, sleeping on a sofa bed.