Is a mid life crisis normal at 40?

I was told that I was having a mid-life crisis when I was getting divorced. That was 3 years ago and I am now 36. I bought a Mustang and went out and partied a lot and met strange woman. It was a good time but during the whole time something was missing. I messed up a lot too... I regret almost everything except my Mustang. I still have that green beauty...