I see. Yeah I get that. I always found it strange though how you can see and hear things that aren't really there. Eariler I had seventh wave stuck in my head, with my own made up music video. It rocked. 
Amber wrote:oooh oh oh. Something I've always wondered
How does one see things/hear music and such in there head? Because... You're not really seeing/hearing anything. But you can still see/hear it.
Maybe I should take a trip to google.
That's where your sensory organs come in. The nerves in your eyes and ears break down the information you are provided with in a manner which your brain can interpret. This is done using complex processes, and the information is reassembled in a more palatable form so that your brain can understand it. After that, it records the information as an electric current which is interconnected with other relevant semantic memories in what is called a "node". On a somewhat related note, the prefrontal cortex of the brain plays a huge role in the utilization of this information at a later date. A subconscious level of your brain re-iterates what you have already experienced (even as you are undergoing new experiences) and the active part of your brain may pick up on pieces of information which seem interesting or relevant to whatever you are doing in the present. This is why you get a song you haven't heard since the mid-90's stuck in your head in 2009.
Edit: Oops, sorry. Ninja delete and repost.
