Before I got my car, I used to walk 30min to and 30min from lectures every day. During that time, I often just recited material to myself. I wouldn't want to go through a tape of lectures (blech, what a waste of time for me), but reciting the life cycle of HIV or rabies from my head or just pondering random stuff like what to cook for dinner this weekend worked fine for me.
Believe me, you can totally afford to think of nothing but beer and football during those 10 commute hours a week, if you really want to. There's a lot of time during the preclinical years, more than you realize before you actually get there. Sometimes I used my longish walk to just relax and unwind.