Correcting people that you don't know

[gusmahler]

What do you do when you're around people that you don't know and they start talking about things that are completely wrong?

I was at a kid's birthday party the other day, playing with my daughter. The guys next to me were talking about going to Vegas. One of them was talking about his fool-proof roulette strategy--since the house advantage stems from the 0 and 00, his strategy is to only bet 0 and 00. The odd thing is that he did know what the house advantage was and where it comes from. But I have no idea how he thought that betting 0 and 00 only would result in a winning session for him.

If it were people I knew, I would have corrected his thinking. But since I did not know him (and for all I know, he could have been joking), I didn't say anything.

How do you react to things like this? It seems like, when I do interject myself by correcting others, they think of me as some kind of annoying know-it-all.