Certainly a physics professor would generally remember what it was like to take their first physics class, what confused them, what way of thinking made it clearer, etc.

I remember that it was all pretty straightforward and intuitive. This was not a typical experience, and it also means that I don't really know what average students have trouble with in basic Newtonian physics. Physics professors tend to be people who were unusually good at introductory physics classes. (Meanwhile, I can't seem to find an explanation of standard social skills that doesn't assume a lot of intuitions that I find non-obvious. Fucking small talk, how does it work?!)

Most professors weren't typical students, so why would their recollections be a good guide to what problems typical students have when learning a subject for the first time?