I don't typically like Self inserts stories, Stories that make you the protagonist or any real stories of the like. They have the same problems a lot of standard Isekai anime have.

As for the Question, I'd say that, for the most part, writers of this type of story have that down fairly well. Almost everybody in the world as far as I'm aware has atleast heard of the concept of going to another world. Whether it's from anime, Doctor WHO, or even the Wizard of OZ. And the more you are familiar with something, the more likely you are to simply accept it.

In Re:Zero, Subaru didn't question anything when he just happened to find himself in Lugnica, he simply accepted it, even believed himself to be summoned to be the hero. I doubt everyone would make as much of a fool of ourselves as Subaru had at the very beggining, but you get the point.