"...we're talking alternate histories, here, it's almost certainly not whatever happened to you.
"The first you I'm aware of is from the 20s—wait, no, 40s—and when he was a child he and his siblings found a magical wardrobe in their uncle's house that took them to a fantasy land written by a devoutly Christian author. Shenanigans happen, they kill an evil witch, they become the four reigning monarchs for a while, there are talking animals, decades later they find the way out of the wardrobe again and find themselves in the bodies of—themselves—as children, again, in their uncle's house. There's more books and also movies but I haven't actually read the books and I haven't watched the movies in forever because I felt like it'd be rude to my version of you to try to do a character study of who he is based on the fictional materials he features most heavily on.
"And, well, my version of you is a boarding school student from an Earth that tends to attract interdimensional visitors for one reason or another, and I'm one such visitor that was attracted. He is as far as I can tell a perfectly normal teenager."