We've all done it. Run upstairs to get your keys, but forget that it is them you’re looking for once you get to the bedroom. Open the fridge door and reach for the middle shelf only to realise that we can't remember why we opened the fridge in the first place. Or wait for a moment to interrupt a friend to find that the burning issue that made us want to interrupt has now vanished from our minds just as we come to speak: "What did I want to say again?" we ask a confused audience, who all think "how should we know?!"
Although these errors can be embarrassing, they are also common. It's known as the "Doorway Effect", and it reveals some important features of how our minds are organised.
