The bartender asks the man sitting at the bar, "What'll you have?" The man says, "A scotch, please." The bartender hands him the drink, and says "That'll be six dollars," to which the guy replies, "What are you talking about? I don't owe you anything for this."
A lawyer, sitting nearby and overhearing the conversation, then says to the bartender, "He's got you there. In the original offer, which constitutes a binding contract upon acceptance, there was no stipulation of remuneration."
The bartender was not impressed, but says to the guy, "Okay, you beat me out of a drink. But don't ever let me catch you in this bar again."
The next day, same man walks into the bar. Bartender says, "What the heck are you doing in here? I can't believe you've got the nerve to come back!"
The man says, "What are you talking about? I've never been in this place in my life!" The bartender replies, "I'm very sorry, but this is uncanny. You must have a double."
To which the man replies, "Thanks. Make it a scotch."