Helen,

My unofficial survey indicates that people over 50 love this joke, and those under 50 hate it. I personally love it.

...in a bar, in Chicago...two guys are talking...

1st: You look familiar.
2nd: You do too.
1st: I grew up in Dublin.
2nd: So did I!
1st: I went to school at St. Mary's.
2nd: So did I!
1st: I graduated in '93.
2nd: What a coincidence...I did too!

Third guy enters the bar and says to bartender, "Anything happening today?"

Bartender says, "Nah, not much, just the Murphy twins drunk again."