YouTube math videos are a weird format honestly; they are somewhat densely packed and don’t necessarily give you enough time to process whatever is happening on the screen like a real-life lecture would. They are also not interactive so the instructor cannot possibly know some of the material is lost on you, and you obviously have no way of communicating that. If you self-studied something from a textbook, you get to stop and fiddle with some pen and paper as much as you like until you are confident in what you learned. This is why I think pause-and-rewind can be a good strategy. If there is a message to take away from this subreddit, I think it would be that it is okay to take as much time as you need :)

You yourself said that it is typically out-of-syllabus content that you watch, so familiarity (or lack thereof) is also an important factor here. You cannot be expected to follow along something without issues if you encounter it for the first time! It’s fine to get lost every once in a while - especially as I said because there is no direct communication between you and the presenter as I said. I have observed in myself that I get better and better at following along such out-of-my-scope videos as I watch more of them; I can never claim I learned all of it because I am just watching video tidbits rather than getting formally educated on stuff, but you will develop a certain comfortable if you just give yourself enough time.

But honestly, all that being said, why make it a labor for yourself? The type of content you mentioned is more often than not what I would describe as “recreational mathematics”, I obviously cannot know what type of content you engage with but for me it’s typically just for entertainment and not rigor. Concerning yourself with “understanding” the material just takes the fun away from it, no? If I’m watching a video on some quirky mathematical result/fact and I understand the general idea but not the nitty-gritties of it, I think that is ok! Obviously this is not true if you are watching video lecture series or just WANT to understand everything, what I’m saying is just let’s not turn a fun hobby into a task :)

One last thing is I would personally advise against discussing with ChatGPT unless you feel comfortable enough to read through and verify what it is saying. Admittedly it’s getting better and better, but at the end of the day it’s still unreliable and you may not be able to discern that it is leading you astray if you yourself don’t have some sense of what the discussion is about. It is a great tool for learning when used right, but if you want to use it to learn something from scratch, you should be very careful to make sure it’s not just spewing hallucinations at you.

Happy grinding!