Depending on what branch you go in, your 1st few years will be busy with different types of schools, deployments, and so on. Take it from me, when I joined the Navy, my first 6 months I was busy with boot camp, a few schools, then off to my first duty station in Japan. Thats another thing to...
It's no joke when you say time flies as you get older. The 11 1/2 years I served in the navy flew by, now I have until April of 2012 until I finish my degree. Seems just like last week I started my degree.