There was a great video on how a car’s differential works where they start by building it out of sticks and demonstrate how to progress from there to helical gears. That approach made it click for me while nothing else did prior, including playing with an actual differential.
I agree it's a great explanation, and the video format feels right for this. Still, it's not the video per se that makes this great, but the way the concept has been broken down into simple (almost unmoving) parts for you, and is then built up in steps.
