Our house has lots of stairs. Some bedrooms are on the ground floor whilst living rooms are above. We sleep above that. Stairs are how we get around.
The hallway down below is rather dark when the bedroom doors are closed. There are seven stairs down to it from our main lobby. It seems like six, but that last little devil, hidden in the shadows, has caught me out once too often!
I've rigged up a handrail gizmo that gives me a reminder when I reach the sixth. Not sure which is worse, electric shock or falling arse over tit!