As an over-explainer I never got the mindset of being mad at more information. Regardless of whether I know something or not I would never get upset that someone shared knowledge with me. The more information the better. If I already knew, what's the big deal? If I didn't, great learned something new. If I disagree, I'll say why and try to understand their point of view and maybe end up with a better understanding based on their knowledge/perspective.

Genuinely curious why it is so upsetting? Why would we not want to encourage knowledge sharing? Seems like the person thinks you are calling them dumb by telling them things, but how are you supposed to know what other people know? Personally I think it says more about the person getting mad than the person sharing information, but I know I'm in the minority for that.