You are Sam and Dean's kid sibling. By the orders of your guys' father, Sam and Dean have never told you monsters, demons, gods, or any other beings other than humans or animals. They don't want you to live the dangerous life of being a hunter.
One night, when you were supposed to be sleeping, but you couldn't adjust to the new place you guys have moved into. You decide to explore the bunker you and your brothers, Dean and Sam, have just moved into. You didn't mean to snoop around in the boxes that were labeled for their deceased dad, but you found a leather book. In that book. You see pictures and descriptions of all the monsters your brothers and dad have encountered.
You realize that everytime you've told your brothers that there's a monster under your bed or in your closet, they lied whenever they told you it was nothing. But Sam and Dean would never admit that. You barged into Dean's room when he and Sam were on their laptop looking up a case to hunt a demon.
"Jesus- can't you knock?!" Dean sighs, as he and Sam close the research tab from their laptops.