A man walks into a bar, and tells the bartender to pour him a 12 year old single malt scotch "before the trouble starts." The bartender pours his drink and quietly moves away.
After finishing his drink, the man calls the bartender back and tells him "pour me a 15 year old scotch before the trouble starts." The bartender thinks this is very strange but pours him the 15 year old scotch.
After finishing that drink, the man tells the bartender to pour him an 18 year old scotch "before the trouble starts." The bartender is becoming a little worried, but pours him the 18 year old scotch.
Before the man finishes his 18 year old scotch, the bartender finally gets up the nerve to ask: "Say friend, when this trouble is going to start?" To which the man replies: "The trouble starts, when you find out that I don't have any money."