The Donut of a Military Career

I was contemplating the length and course of my military career as I prepared my last two posts. It appears that should I hang on as long as allowed (I don't think I will make it to Brigadier General, heh heh), I have already completed over two thirds of my service. I am finding it increasingly difficult to remember what it was like not being in the service. I am 39 years old, and I have been in since I was 18. I often wonder how I will feel about it when I retire or get pushed out for whatever reason (age, health, etc.).