It's not that we're in a comic book... ok, see, if you read them, you'd get this better. BUT.
Basically, there's tons of realities. Like.... worlds where fictional shit in our world is real. Worlds where Germany won WW2. Worlds where dinosaurs never went extinct. Worlds where gross orange facists become US president. It's called a Multiverse.
Still learning about why we're here... but it's kinda like people from all over the multiverse are getting pulled into other realities. Neat, huh?