There are some people who work in my building (not on my floor) who get on the elevator in the middle of a cell phone call. Inevitably, these people end up shouting "Hello? Hello? Can you hear me?" into the phone before looking at it curiously. I'm talking about full-grown adults who have lived in the cell phone age long enough to know when and where cellular network coverage is available. The elevator is not a place where one can expect to get full bars or even one bar. It's in the middle of the building, surrounded by steel and concrete. Elevators are where cell phone signals go to die. Yet these people check their phones like dropped calls are a mysterious phenomenon never before experienced by human beings.
These are also the same people who answer the phone on the subway while the train is above ground, then shout "hello? Hello?" again when the train goes underground. Your phone is not made of magic, sir. It does not work in the bowels of the city (and we like it that way, lest we all be subjected to your inane conversation for our entire journey). Why don't you put that thing away before you hurt yourself? I'll give you a dollar and you can get yourself a candy phone to play with. Enjoy!