What am I? I am a creature wanting to better myself and have things better for myself. Is that what I am, or is that a story about what I am? Is there a difference between the story of what I am and the reality of what I am?
If what I am is the story, then it would follow that by changing the story I change what I am. Thus, eating a pear instead of a peach would change my body chemistry to some extent, and I would be a different person than if I ate the peach. I would be a different person if I drove the longer route to work. Different by thinking new thoughts. By marrying someone else. By becoming ill.
Here's how it works. What follows is the general theory behind the practice of self-inquiry, a practice consisting of no more and no less than simply asking the question "What am I" whenever it occurs to you to do so.
We start with the premise that our natural state of being does not include suffering. Suffering is an add-on. It is a pattern which develops out of the function of our mind which has to do with picking and choosing and rejecting. This function is a simple binary code: I want this; I don't want that. Over time we build up a belief about what we are as a direct result of this interplay between the want/don't want function and our life experiences. That belief - and nothing else - causes the suffering. What we believe ourselves to be - a person needing this or that - is not true. The truth of what we are is the cure for the false belief. Each of us is a person who is here. Seeing the truth of that statement eradicates the false belief.
Sometimes it's virtually impossible to conduct the inquiry. When you're in a total funk in Bogoland, for example, or when there's something running wild in your mind that you can't shake. Even when you have enough moxie to force yourself to ask the question "what am I?" or to get a sense of what it feels like to be you, you may find the door is closed and nothing you do will seem to work. It will be like opening the manhole cover to a network of tunnels you knew existed and find concrete instead. Totally impenetrable.
