I want to learn so that I can eventually discover something unknown, and contribute to the collective pool of human knowledge. The way I see it, everything I know has been known by someone else at some point. I want to discover something, to be the first person to know something and show it to others. To reach that point, I have to learn as much as I can. I also think its amazing that I have access to information that people labored their whole lives to produce, and in some cases fell just short of. Archimedes would have killed for a modern calculus book, one that is readily available to me. It seems almost disrespectful to these great people to just pass this information up out of apathy. Also, there's the general sentiment that knowledge is its own reward, which is also true.