I took some notes, but without a precise goal (like passing the final exam), I was mostly interested in getting a bird's eye view of the topic and in typical "collector" mode, I bookmarked a significant number of resources mentioned in the reading list or in the lectures, most of which I scanned but did not read. I collected and organized these resources in Pearltrees.
So, what did I learn?
Did I learn less, as much, or more than the average student in that class who attended the face-to-face lectures, interacted with the professors, and presumably, did all the assignments? I suspect I learned less, but that's just fine. My goals were different and my goals were met.
Besides the course materials, I learned a lot about what I like and don't like about Pearltrees.