A man walks into a bar and orders two beers. He continues this for several nights and the bartender gets a bit curious.

The bartender walks up to him and asks, "Sir, why do you always ask for two beers?".

The man replies, "I used to come here with my best friend, but now he's dead. So I'm drinking the second beer on his behalf."

A few days later, the man orders only one beer.

Curious, the bartender asks him, "Why only one beer now, sir?".

The man replies, "I have given up drinking!".