They still need to actually learn the stuff. That's my point based on your original comment: You're comment was comparing work to school, and that normal schools were bad in some way because at work you could miss time and someone else would step in. I said, repeated, and will say again: learning does not work that way. No one can step in for you. Montessori doesn't change that. It changes the timing and, sure, the direct pressure from the teacher. That doesn't mean there isn't some type of pressure: from the parent, from the other students that are obliged to help in their co-operative learning structure, etc.

I'm not debating the merits of Montessori schools. I'm saying the "missing time" aspect of your comment does not have a good analog from work to learning. That's all.