Evan becomes very sad and very angry when he is left behind on the main floor when an adult goes upstairs or downstairs. I try to sneak away when he's not near the baby gates. Unfortunately our baby gates are wrought iron and the closure mechanism is loud--CLICK! He hears it even when he is out of sight of the gates and he comes racing. If he's far enough away and I leap the stairs fast enough I might be out of his line of sight when he gets to the gate. Sometimes he'll be fooled into thinking it was a false alarm and he'll quietly go back to playing, but other times he is not fooled and he screams about the injustice of being left behind.
Lincoln was never this bad...although there was that period of time when he would hold his breath until he passed out if he was left behind. Passing out on a hardwood floor is not a good idea. But still, Lincoln wasn't as diligent about watching and listening for anyone going upstairs. And if we let him come upstairs with us, he wasn't a tornado of chaos like Evan.