[westoncb]

It being boring to me would be a rude/invalid reason to interrupt, I mean the case specifically where someone is telling/explaining/describing something to you because they think you don’t know about it. The interruption is just to let them know that you do already know about it, not to change the subject. I would find it embarrassing if someone let me going on telling them something they already know just because they thought I didn’t want to be interrupted.

But thank you more generally and I’m sure we’d have a good conversation!

[dasz]

Sometimes I let people explain something I already know because they either explain it better or add more detail. Even a well described reminder is useful and interesting if told well.

Sometimes though it's not useful and it's them explaining poorly or, even worse, pointless simplification. They'll get interrupted fast if either of those is the case.