Who is familiar with ending up in alternate realities that are so similar that it takes a you a while to realize the differences?

This is the one thing that would for sure make you pass for crazy but when you know you know. And you cannot truly talk about it with anybody else. I know there are subs that are dedicated to it. I like the PP sub because many of us have a bigger picture of reality. It would be great to connect to others who experience this too.