Inception explains that every character has a totem, which is exclusive to them and tells them whether they’re dreaming or not. We’re told that Dom Cobb’s totem is a spinning top, which leads to the movie’s frustrating cliffhanger ending where the top continues to spin as the screen cuts to black. But a fan theory suggests Cobb’s totem is actually his wedding ring. He even reveals at one point that the totem first belonged to his wife, and if you watch closely, you’ll see that while he’s dreaming he wears the ring. But when he’s awake, no ring. It’s one of those little movie details that only the keenest observers would notice, and thankfully someone did.