The most annoying situation is when I open a video, wait to skip the advertisements, then immediately seek on the timeline to a spot of interest without watching more than a couple seconds, and another set of advertisements then play.
I can't say that I remember those advertisements. With autoplay disabled, YouTube shows a static picture with some writing that doesn't burn into memory. I still have to wait to skip it. I think the new Opera browser was shown, but maybe that was a sponsored segment.
Since the blocking on YouTube is now very complicated, I haven't even invenstigated what I need for it, and keep that thing updated.