In the original Toy Story, we meet a troubled boy named Sid, who tortures and breaks his toys. To get revenge, his new creepy creations come to life to scare him. Then in Toy Story 3, we see a young man wearing Sid’s trademark shirt, a black tee with a skull on it. In the trilogy, Sid is the only person to have seen toys come alive, so the theory is that he feels guilty for the “alive” toys going into the grinder. So now we believe he becomes a garbage man to save them from their grisly fate.