I think you completely misunderstood this interaction.
There are 2 possible explanations.
1. You are so smart/knowledgeable that the professor thinks you are beyond college.
2. You were acting like such an arrogant know-it-all that the professor was being sarcastic.
I’ve seen #1, but I’ve seen #2 many times.
You sound like you have a huge chip on your shoulder about not having a degree. I had the same issue at one point before I went back and finished (after working as a professional developer for a while), so I recognize it.
When I did go back, I asked questions in class, I went to office hours to ask questions, and I did research projects with professors. Some back of the envelope math says it would have costs me about twice what I got out owing if I’d paid for an equal amount of time with whatever experts I could find.
My strong suspicion based on the few posts I’ve read is that your attitude is the reason you had such poor interactions with instructors.
Chip on my shoulder - no, and it's a silly label to begin with. Understanding that it's for other people who value the paper more than intrinsic understanding, yeah.
EDIT: I will concede in some way that I'm proud of not having a degree, and it does influence my thoughts on this topic. I've met some real idiots that do, and I don't consider it a serious differentiator.
Also looking up the thread - at my early jobs, I was surrounded by many people who were interested in educating me on any topic I could think of, because similarly we were all being paid for our time. The difference between that and school was the assumption that we were both motivated and capable.