The back of my mind's mind

I am a geek.
I am back in school after an almost 11 year hiatus and I am loving it. Sure there is no homework, readings or papers due just yet but being in the classroom scribbling notes in a notebook and in general "getting it" (well, most of the time anyway) is SO MUCH FUN!
Of course, there are other activities that are more fun but it is truly fulfilling. When I am in class, I certainly have time to let my mind wander, but when it does, in the back of its mind (yes, the back of the back of my mind) it has a calm feeling knowing that I am sitting there for a reason and towards a goal. So, no - not FUN but fulfilling. And isn't that a fundamental portion of fun? (Love the pun, don't you)