 Other philosophers reject this picture. They argue that you persist through time as a whole: it’s not just a part of you sitting in front of the computer right now, it’s you, the whole you! It was the very same whole person yesterday who knew nothing about temporal parts, and, by tomorrow, the very same whole person will be an expert. ‘You-yesterday’ isn’t a name for some mysterious part of you which only existed for a day; instead, it’s a stilted way of talking about you, and what you were like yesterday.