He is a very fast drinker
A man goes into a bar and seats himself on a stool. The bartender looks at him and says, "What'll it be buddy?"
The man says, "Set me up with seven whiskey shots and make them doubles." The bartender does this and watches the man slug one down, then the next, then the next, and so on until all seven are gone almost as quickly as they were served. Staring in disbelief, the bartender asks why he's doing all this drinking.
"You'd drink them this fast too if you had what I have."
The bartender hastily asks, "What do you have pal?"
