A retired mechanical engineer spends his time making videos of mechanical linkages in CAD. He's was at 1700 a year ago, hard to say how many he's at now, he's still releasing them. This is what technological progress looks like I think, in a couple of years this will be shown in just about any intro class into the subject and it will reduce the learning time by like, i don't even know, 100x? 1000x? Idk how these were described before but boy do they seem hard to describe in anything but animation.

I'm also having a hard time imagining his brain isn't getting exercised just fine.

I'm not a mechanical engineer and I spent like good 15-20 minutes watching them and getting quite a bit out of it.