"Some say our memories are what make us us, but basic physics dictate that our memory has finite capacity. New memories supplant the old and the strongest are t

"Some say our memories are what make us us, but basic physics dictate that our memory has finite capacity. New memories supplant the old and the strongest are those recalled and refreshed frequently. Given a thousand years to live, you could conceivably forget everything you now know. Personal history is a revolving door." Some people have a weird condition where they remember EVERYTHING from a certain point in their lives, they never forget anything. I'm sure they have a finite amount of memory, but it's so big it's infinite in practice.