Well, in fact, you are not actually walking in this world. Or, more accurately, you are walking in two worlds most of the time. One world is a virtual reality map made up entirely in your head. Your brain is moving your human form through the virtual map it has created, which is why you can move through your house fairly easily in the dark; you are not using the external world to navigate. You are using your brain map to get around this familiar space, with your human body arriving where your brain has sent it.
