8.6 Years

So I did the math today and realized I still have 8.6 years left on my student loans.  Does any one else wonder why you go to school for 4 years (give or take) and pay it back over 10 years (give or take).  Of course I find it intesting, at least based on my own math at the current pay schedule, my private loans will take 8.6 years and my stafford loans will only take 7.6 years.  Somehow, there is a whole year difference. Oh well, I don't mind, really.  I think I will see what I can do to possibly pay these off ahead of schedule, although they currently hit my wallet, rather hard so I may have to hold off until some other stuff gets paid off.