What happens when you are aimlessly thinking about random matters

I have just came across a random thought. We all know that everything we do depends on our brain. If our brain was a part of "us"(let's take us as a general term) it means that "we " are controlling our brain. But what is that thing controlling our brain if the brain is the one controlling everything?

Another point. If we say everything in our body can be controlled by us, including our brain, then i think that this statement is wrong. Since our brain controls our nerve cells, why can't we control the pain that we feel? This leads to the thought that our brain controls us. But if I'm thinking this right now, what is the thing, or cell, or substance that feels that my body is a "totalitarian" state and my brain actually wants me to enjoy feeling pain? One understands that pain is necessary so that we know that our body is in trouble but one wonders why the brain could not have just sent one a message saying " you body is hurt. Do something about it" . One would have gladly thanked it and seen a doctor immediately.

So at the end of this of this philosophical(ahem) cum B**ls**t post, I ask one question : What the hell are we???