Mansplaining is a thing, sure. lit happens. But I think a key aspect of it is talking down to someone. Its explaining things like how to turn on a computer or telling an engineer how to do addition.

My head is filled with mostly useless facts. I've learned that if im talking to someone about something I'm interested in chances are they'll have never heard of it or no nothing about it. So I make sure to ask things like: do you know much about x? Or have you heard of you before?

It gives me an idea of how much I'll need to explain. Ive had a few instances where someone has gotten indignant to the question. To which I normally reply by jumping right past first principles and into to the heart of it. Cue confused look.