When I was working as a Receiving Clerk at an army surplus in Detroit, I rarely had contact with the customers except for those rare (and hilarious) occasions that I had to go out on the floor to set up or move stock.
At the end of the day, almost closing time, I go out on the floor to pull some seasonal items into the stockroom for storage. Low and behold some guy sees me come out of the backroom and asks me a question, he wants to find a canteen. Alright, no biggie, I take him to the isle with the canteens and show him the different ones. He looks at quite a few and ask questions like capacity and what they are made off. Finally he asks the question: "Which one of these would be best suited carrying Alcohol?"...... ok.
So I show him the steel and tin canteens. He chooses a larger steel canteen and says thanx. As he walks away I say that if he prefers we have flasks made specially for caring alcohol. He frowns and says, I am quoting now "Only alcoholics carry flasks".
I barely got back to the backroom before I doubled over laughing