As a tank I don't watch videos, that's just confusing to me. I'd much rather read what actually happens.

That way I know what effects the different attacks have, like what are the tank busters, what requires that I move the boss, what should have priority, etc.

Then it's just a question of trying once. When you've read what's supposed to happen it becomes rather easy to recognize it in game and do what needs to be done.

I wouldn't say I "remember" them, but most mechanics are "secondary" throughout the game (I assume endgame alone is different, where you can do fewer mistakes), so I remember the ones that matter, the ones that mean wiping if done wrong.

You know how it goes, when you're against a boss you've done before and you have some bad memories, but you don't know what exactly, then it does something and the whol group is left with only a few HP and then you suddenly remember, "oh right, we had to..."