The human brain is an amazing thing, it has the ability to hold every peice of information that it will ever recieve. It can be anything that at one point you read or saw or heard, maybe even smell. This happens to everyone, but intellegence is something that is interesting. Since everyone can remember the same things if they have the ability, then why are some people smarter then others? It's becuase some people actually can control how to access this information. Like in the movie Limitless, which Bradley Cooper, he takes a pill that allows him to recall everything! One of the better scenes to display this is when he is talking to his landlord's girlfriend and he sees a book and recalls the last time he saw it and was able to peice together that she is a struggling law student. Now this can happen to anyone, everyone has the abilitty to access this information, but now the brain also blocks information, this way there isn't an overload of information, like when you are talking to someone in the caferteria, you don't hear everyone talk, you focus on one thing and register that with more effort, despite all the other sounds being taken in. It's really wild! http://voices.yahoo.com/how-much-information-does-brain-hold-2839851.html