There's just one thing that I don't understand: on a bike, with the hands of the handlebar, I can turn right by leaning right, but I don't understand how leaning right would cause the countersteer left.
Here's another video that helped it click for me when I didn't get it either https://www.youtube.com/watch?v=PgUOOwnZcDU It's more "phsyics-ey"
When your hands are off the handlebar and you "lean right," the handlebars won't visibly "turn left," and if they do it will only be for the briefest moment. It only takes the tiniest countersteer to cause the "lean angle." It has to happen because your handlebars are non-rigid.
Let me know what you think after the video above. IIRC it has the "rolling cup" example, which for me works best.
I watched the video above and another one and I'm getting it a little better. Also another thing is that recently I've been riding a bike rather slowly, at speed where countersteering is not necessary and less visible, as shown in another video (https://www.youtube.com/watch?v=C848R9xWrjc). And as for countersteering while the hands off the handlebars, I realise that usually my eyes are on the road, not the handlebars, so I'd easily miss the brief countersteering.
Thank you for your patience too!
I meant it more as a comparison between anecdotal evidence vs research evidence. I.e., someone saying "I've never seen a fire, I'm not sure why we need to bother with fire drills."
Maybe better would be "why bother getting vaccinations, I've never seen a bacteria in my life."