The guy went in his neighborhood bar every day, and ordered two double bourbons on the rocks at the same time. He's slowly sip from each one alternately, then leave. One day the bartenders curiosity got the better of him, so he asked about it. "Well, me and my buddy Spike used to do that at the enlisted club every night, but he got blown away by an IED in Baghdad, so now I have to drink his for him. After a few more months went by, he started only ordering one drink. The bartender asks "What happened to your drinking buddy?" The man replies "Nothing happened to him, but the doctor says I have to stop drinking."