State of memory and mind where you know everything ever seen, felt, heard, etc., but do not know how to access it, thus making your thoughts very random, as it just spits out random memories, thoughts and musings. To own one makes you very intelligent, yet also very stupid and random. People with a void eidetic mindset are typically very entertaining to be around, as one minute they will hold a deep philosophical conversation with you, the next they'll be acting like the biggest idiot you may know.
Person 1: You here about that one kid over there?
Person 2: No, what about him?
Person 1: Well they say he's got a void eidetic memory, that's why he's all goofy, but whenever we talk to him he seems excedingly normal.