Doorways are magical. We are on one side and all these things are true and then when we walk through the doorway, all of these other things are now true. There is something called the Doorway Effect. 

The doorway effect, also known as the location updating effect, is a psychological phenomenon that causes short-term memory loss when moving from one location to another or passing through a doorway.

The doorway effect can be explained by the idea that boundaries help us segment our experiences into separate events, making them easier to remember. When we move to a new event, we may flush out information from the previous event because it may not be relevant anymore. The doorway effect can also be explained by the idea that our attention moves between levels, and when we change both our mental and physical environments, we may forget our goals. For example, you might run upstairs to get your keys, but forget what you're looking for once you get to the bedroom.

The doorway effect was first observed in a study where participants walked through a doorway into a new room and then took a quiz about what was in their backpack. The participants' responses were slower and less accurate when they walked through the doorway.