It's good to pace yourself when it comes to drinking.
John who's had five alcoholic drinks already is at the bar when the bartender asks him what else he wants.
John wants to respond to the bartender's question.
John tells the bartender that he just wants water now as he needs to get some hydration back.
John tells the bartender to make him another whiskey sour and to make it a double.
The bartender thinks John is a smart man who's a good customer and feel safe about having him in the bar.
The bartender thinks John is a lush who has no self control and is scared of how this night will turn out.