It would be strange to allow strangers into your home whenever they wanted to come over for a drink. They could be criminals, living in the same neighborhood as you and your family. Usually, you invite people over to your place only when you feel ready to, because you can have fun and it’s safe and they’re safe. They’ve been vetted . There was a process , and it clicked. That’s it. It’s human. Even at the cellular level– where the smallest animal cells have some semblance of border or a wall.