A man walks into a bar. The bartender says to the guy, "What can I get you?"
"Make it a whiskey," says the man who promptly throws it down in one gulp.
"That will be three dollars," says the bartender.
"Screw you!" says the man. "You offered to get me something. I thought you were paying."
"Get out," says the bartender. "You're banned. I don't need your crap."
Two years later, the same man walks into same bar with the same bartender.
The bartender looks at him and says, "You're the a**hole who tried to con a drink out of me, aren't you?"
"Excuse me, but I have no idea what you are talking about," says the customer. "I've never been to this bar before in my life!"
"Sorry. My mistake," says the bartender. "You must have a double."
"Hey thanks, dude!" says the customer. "Make it whiskey."