I never really got the difference between the dot and cross products until many years after graduation. And then I only got it because I managed to stumble upon

I never really got the difference between the dot and cross products until many years after graduation. And then I only got it because I managed to stumble upon a good video with somewhat decent animations. Like, 2-D, sure, seems easy enough. But once you go to 4-D, things get really hard to grok. Passionate science educators online have really filled in a lot of my education.