It is certainly valid to claim that one can learn things this way, but it hardly seems to be the purpose of schooling. If I could read a 45 minute lecture in 7

It is certainly valid to claim that one can learn things this way, but it hardly seems to be the purpose of schooling. If I could read a 45 minute lecture in 7 minutes, I would then have an additional 38 minutes of question time. It's even more inefficient to sit in a classroom full of people, listening to "customized" questions asked on subjects that you fully understand. The scenario that bugs me the most is when a fellow student asks a confused question that indicates to me he has understood very little of the lecture, the instructor then proceeds to answer it poorly, which then confuses other students.