 Some philosophers believe that you take up time by having different temporal parts at different times. Your spatial parts are things like your head, your feet and your nose; your temporal parts are things like you-yesterday, you-today and you-tomorrow. If you have different temporal parts, this would explain how you can exist at different times, and it would also explain how you can have different properties at different times (you-yesterday hasn’t heard of temporal parts, you-tomorrow is an expert). According to these philosophers, then, persisting through time is pretty much like extending through space: it’s all a matter of parts.