I never like saying hello to someone I know when I see them totally out of context. For instance, if I see someone I know from L.A. crossing the street in Germany and they don’t see me, I probably won’t say hello. What are they doing all the way in Germany? What if they’re a spy or doing something diabolical and now they have to kill me because I wasn’t supposed to see them. I don’t want to be the guy who doesn’t make it home because he broke his back to say hi. And even when I see them back in our original setting, I still won’t mention that I saw them. I might casually drop a hint:
ME:You know I was in Berlin last week right?I had a good time, gotta love that Bratwurst.
And if that person doesn’t immediately own up to also being in Germany then I know my unfriendliness may have saved my life.
I recently broke my own rule and said hi to a comic I know from LA when he walked past me in Seattle. Luckily for me he either was not on a top secret mission or he was but had a good enough excuse that he didn’t need to erase me.
But by all means, if you see me out and about in some far off exotic place please say hi…at your own risk.