I can remember times being a student, learning a lot, but losing focus of how amazing it was I had dedicated time solely to study. As someone working full-time now, who only gets to learn new fascinating math in his precious free time, I implore you to fully embrace the awesome opportunity in front of you. Enjoy the lecture, and milk whatever you can from this man's teaching.
Similarly, I am glad I did not have a laptop/smartphone with wireless Internet [in the classroom] in my college days. I fear I'd have learned so much less. In fact, there's a pretty strong correlation between my study results going down the moment we got cable Internet at my students-home... :-/
(on the positive side, Internet made me loads of international friends, and there's truckloads of things I could not have learned without it)
You just made me realize something. I attributed my own college grades slipping a bit my senior year to burnout, but it was also Fall '08, and I had just got an iPhone 3G, my first smartphone...