For me the heart of the issue is all about learning. I reflect back on my pre-college years, and I remember very little of what I "learned" in classrooms. For the most part, basic skills acquisition aside, I learned to memorize whatever it was I was required to know, and then rapidly forget it after the test.
What I do remember are the moments of new understanding, when something that was puzzling or interesting to me suddenly became clearer. Those moments emerged in the (what I remember as rare) instances in which I was actively participating in thinking about whatever was being taught. When what we were doing in the classroom was examining some event or idea or concept, and not just being told what it meant. That moment of clarity, when learning comes alive, when a new connection is made or a new way of thinking illuminated. For me that is what doing pre-college philosophy is all about. Because by definition philosophy involves exploring the meaning of unsettled questions and concepts, philosophical inquiry is especially capable of generating such transformative moments. And it is in those moments, I think, that real and deep learning really happens.