This guy comes into a bar and orders three separate shots of Irish whiskey. He downs one, engages in casual conversation with the bartender, eventually finishing the other two.
This goes on for a few days and the bartender finally says, "You know, I can put all three shots in one glass for you."
The other gentleman replies, "No, I prefer it this way. See, I'm very close to my two brothers. They're both in Ireland now and this represents a drink for each of us. This way I can be closer to them and feel like we are all having a drink together."
The bartender agrees and continues to set them up as requested.

This goes on for several months, and then one day, the guy orders two shots. Well the bartender begins to worry that maybe something has happened to one of his brothers. He's gotten to know this guy over the month and finally feels it necessary to ask.
"Is everything all right?" the bartender asks.
"What do you mean?" replied the gentleman.
"Well," the bartender said, "all these months you've ordered three drinks. Now you've only ordered two. Something didn't happen to one of your brothers, did it?"
"No," the gentleman replied.
"They are okay. It's just that I quit drinking."