how do they find me?

All these guys who can't manage a conversation with anyone else...how do they know I can understand their slurred or accented speach, where noone else will? In a bar, with 4 seats open, how does the jamacian marine with a big chip on his shoulder, know that I'm the one guy in the bar who'll be polite to the extreme? Any other man, when we went to the second bar, and some guy one has met less than an hour ago, starts introducing you to complete strangers as "my best friend for so many years", would have said something. Not me though, I pay for a round of drinks, cause I feel bad that my regular bartender didn't warn him my drink is 8 bux, before he 'bought' me the one I was already drinking.

don't get me wrong, this guy seemed OK, much less scary than the one who came up to me in the 7-11 parking lot, but still...wtf....