Word of advice - Vetlanda train station

I had to wait for the guys for a while in Vetlanda. Right after I took this picture a man stepped out from his "bedroom", the left door in the cold waiting hall. We chitchatted for a while and when I was about to leave he wanted to give me a good advise for my journey: "Whatever you do, don’t get sober!" He said. I took the advice with me and thought about the words he said for a while. What could the man mean with that? Could his life be so miserable that he really meant what he said? It’s sad...