Did I mention memory before? I forget :) The brain has a sort of mental RAM, the short-term memory. How does it work, how does it expand, how does it improve? Can it improve? I feel like the monhts of answering phones and taking account numbers over the phone has expanded my ability to retrain numbers in my memory, and retain longer ones, but I'm not sure if I've just actively learned how to do it better or if I really have improved my short-term memory... And how do you wake up with a song in your head? Some chemical that triggers that song in your head is just floating around and as soon as you wake up the song is just there. Sometimes its a song you haven't heard in months but its stuck in your short-term memory- I think it is things like this that illustrates the fact that the brain is largely a complex biological computer, which is truly amazing.