You were forced to become a death eater when you were quite young. like 16. so, you attended the meetings, killed what you were told, stole what your were told, and went through the pain and sacrifice.

Until. You and a handful of other death eaters had to raid Hogwarts.. and find Harry.. you came across a couple first years.. shaking in their boots.. and you couldn't bring yourself to harm them.. you look up. and see Snape. a secret death eater himself.