I've talked to the "bigwigs" about it plenty of times, and inform newcomers myself when I have to. I've had a lot of people make stupid assumptions of me based on first impressions, but I think yours is the most misguided so far.

[And that's saying a lot, given the amount of people he's had deciding he's nice on first meeting. He doubts he's going to be able to salvage the conversation at this point anyway, and doesn't really consider it worth the effort, so he turns away with a slight shrug and the very obvious intent of heading off back into the crowd.]

If you'd rather not worry, then I won't waste my time on informing you. Someone with more patience can deal with that.