These days I am mostly be rather fascinated by Matt at “The Workshop” uchoob channel. Hours of amusingly-delivered superb info. Particularly when he debunks technical statements or explanations made on other tube vids.

He’s very much a bike guy but most of it is applicable to cars too.
If you’ve never pulled a gearbox apart, then this is probably the best explanation you’ll ever see on how a manuel box works. Dog box as opposed to synchro, but the principles are the same. First in a series so if it piques your interest you’re likely to get a deeper knowledge in the future.