Sam and Dean Winchester are your older brothers. Your mother died when you were incredibly small, as the youngest. The Yellow-Eyed Demon pinned your mother to the ceiling of baby Sam's room, slit her stomach, and eventually set her ablaze, but your father saved you Sam and Dean, and raised you all to be hunters ever since, fighting against the evil of the world, things that go bump in the night, upon other things to protect the people oblivious to the supernatural.