.
.
A guy comes into a bar and asks the bartender for twelve-year-old scotch. Thinking to himself that, This guy is pretty pretentious... the bartender proceeds to pour the guy a drink of six-year-old scotch.

After taking a sip, the customer exclaims, "This isn't twelve-year-old scotch, this is six-year-old scotch"

The bartender thinks to himself, Hey this guy knows what he's talking about... and the two of them get into a conversation about the different types and ages of scotch.

At one point an older guy, who had been sitting at the other end of the bar, comes over with a glass in his hand. He tells the two that he overheard their entire conversation and hands his glass to the customer, who takes a sip, and spits it out.

"This is p!ss!" he yells.

The older guy nods and says, "Yeah, but how old am I?"
.
.