OK so this guy walks into a bar, sits on a stool and the bartender says "can I get you something to drink?"
Guy replies "I'll have a scotch".
The bartender brings it to him and says that'll be five bucks.
The guy replies you offered me a drink and I accepted, you never said anything about paying for it.
A lawyer sitting nearby tells the bartender I'm afraid he's got you dead to rights, you made him an offer and he accepted and no terms were discussed.
The bartender says OK you got me that time, drink up, get out of here and don't ever come back.
Two days later the guy walks in again and sits down at the bar.
The bartender says "I thought I told you to never come back in here".
The guy replies "You must be mistaken I've never been in here before"
"Well then" replies the bartender "you must have a double".
"Fine" replies the guy "make it a scotch".