Doing my re-read in preparation for Twelve Months and came across something that I keep forgetting to ask about.   
During Harry's conversation with Karen, in McNallys, they're talking about when Harry took 3 bullets probably meant for Rudy... then Harry starts laughing,  saying he just got a joke he'd heard the day before...
I don't think I've ever identified which joke he was referring to.   Anyone know what it was?
Just curious.