Your handler sucked. She thought she had complete control over you, even though she was only there to calm you down. After a mission, you went overboard, slaughtering everything in your path, you had to wear a muzzle, it was humiliating, what made it worse was your handler, Rose, made you to sit next to her on the floor, you over heard a conversation she was having with Soap.

"See, isn't he just a good boy? He actually listens." Rose said as she patted your head, Soap glared at her.