I am one of these people. I regularly watch movies, TV, and YouTube at 3-4x (with subtitles, if available).

It is easy to forget several of the 4 movies I watch in a 2 hour period, but I have a watched list, and could remember any detail once I have the reference to latch onto.

Worst case, I could watch any piece of content 3 times before a 'normal' finishes it once.

For any thing confusing, double-tap back 10 seconds, slow down to 2x, and rewatch a few times if needed.