A Gloomy Tale

Last week, my husband got up in the middle of the night and fell down a flight of stairs. He thought he was in New York City on a nice flat floor, but he was in the woods of Suffolk County. It was no fun at all, because he sprouted large purple and red maps of the world all over his arms and chest, and his back hurts something awful
So here's what I want to know. Why do they call a flight of stairs a flight? Stairs can't fly. If they could, my husband would have been somewhere over the rainbow by now, and his back wouldn't hurt at all, instead of me dragging him to doctors in the hope that he might be pressed back into one piece. I guess the house in the woods needs to be exchanged for a ranch house that is satisfied to sit on one level. I mean, I myself fell down those perilous stairs three times. Once, my niece's boyfriend picked me up and carried me out to the car, once a kindly old lady picked me up and planted me in a chair, and once nobody else was around, so I had to phone for a taxi driver and a taxi to get me home.
A gloomy tale, but we can't all be laughing all the time.