> The Wadsworth Constant is the idea (and 2011 meme) that one can safely skip past the first 30 percent of any YouTube video without missing any important content.

I heard about this a few months ago, and have since checked when the actual content starts in the videos I watch. I certainly can't agree with 30%, usually in 15-minute videos, the introduction is 1-2 minutes before they go into the meat. The bigger problem is all the filler, sponsorship breaks, "remember to ring the bell" etc., that occur at seemingly random points, though I don't think it adds up to 30% filler even if you count all that. Maybe I just skip over most of the garbage.