When you set it up as a start up application! I've been wanting this for years, didn't know how easy it was to set up in Windows 10! I set up a shortcut link (like the one on desktop) in the system:startup folder and checked it was set as on in windows settings! Now I don't even have to open it!
Watching the PBS station like I always do on Saturdays and the show "This Old House" came on. Usually, I change the channel at that time, but I had been doing something when it started, so it was on for a bit. While the show was on, someone talked about a New England style of house called the "three-decker." It's a 3-story house with a deck in the same location on each level, built in Victorian times. "This would be great to use for apartment lots," I thought. The person then mentioned that families would live in one story and rent out the other two, confirming my theory.