When I’m understimulated by a teacher, my mind wanders. I’ll start thinking about something else entirely. When my mind comes back, I’ll have missed a couple minutes of content. I can overcome this with willpower, but doing so is exhausting.

Playing videos at 1.5-2x fixes the problem entirely. My attention is held without any effort.

If a concept is new or difficult enough, I just slow the video back down or pause it whenever I need to think things through.