We typically think of an education setting involving a school and teacher who determine the lesson plans. The students in these settings are passive; they listen to the teacher and perform the activities he prescribes.
A product manager turns this approach on its head. Product managers learn about the market for their products through proactive learning. We can't rely on someone to come to us with a lesson plan. We create our own lesson plans.
Thus a product manager can't just be a good student. A product manager must be a special breed of student that specializes in proactive learning.