Do you have any light switches in your home that you've walked past for years, and suddenly realized you had no idea what it was supposed to do?

I’ve lived here since 99. In the kitchen I have a plate over one counter with two switches. The one turns the kitchen light off an on. I suddenly realized today that I had no idea what the other switch was supposed to do! I flipped it, and nothing happened.

Have you ever had something like that happen, where something becomes so familiar that you cease to even notice it or think about it until one day you realize you didn’t even know what it was for?