"Why do you always order two drinks?"

A man walks into a bar and asks the bartender for two beers. As he continues this for several nights, the bartender's curiosity compels him to ask, "Sir, why do you always ask for two drinks?" The man replies, "I used to come here with my best friend but now he's dead. And I'm drinking the second beer on his behalf." A few days later, the man orders only one beer. Curious once again, the bartender asks," Why now only one beer?" The man replies, "I've given up drinking."