You're absolutely correct, and that distinction is why the problem is so hard to solve algorithmically. The addition of the angle, "never ask the user to catego

You're absolutely correct, and that distinction is why the problem is so hard to solve algorithmically. The addition of the angle, "never ask the user to categorize something, always intuit it", is what makes this a hard problem. Youtube doesn't know which types of playlists I use, but I do. They're wasting computing time and my time to try and guess the behavior I want, when I could just tell them what behavior I want.