Even when I am perfectly capable of understanding something myself, I find it extremely helpful to learn with other interested people in a "study, study, then discuss" kind of format. I come to my own conclusions about the text while I study, just as I would if I were working by myself, but then I additionally get to compare the details of my conclusions with those of other minds working independently. Also, having participants with diverse intellectual backgrounds means that they may be able to identify and share interesting tangential ideas that would not have occurred to me alone.

I also find that communicating my thoughts to other people forces me to clarify them to a greater degree, often revealing small gaps in understanding that I had papered over in my own mind.