I'd go further and say that as long as a person can keep the listener's attention, they won't sound like a douche. It's finding out all the confounding variable

I'd go further and say that as long as a person can keep the listener's attention, they won't sound like a douche. It's finding out all the confounding variables which makes them sound annoying (e.g. how close you're to the listener, assuming knowledge, mentioning stuff irrelevant to the story).