Just because we all realize that we can't remember the name of the director of the movie we were talking about doesn't mean somebody has to stop and look it up. But somebody will, and they'll miss out on the first minute+ of the conversation, possibly strangling it in its crib.

> Why would we be talking about this if we didn't care about the truth of it?

Mentioning something in passing doesn't make it either the subject or the point of a discussion.