And I thought I was the only one who felt this way. Facing a wall in an open office space causes me to react defensively to noises around me. Is someone sneaking up on me? What's happening in my immediate surroundings? This is not rational, but I don't see any way to make myself stop other than to "handicap" my senses via headphones. Thankfully, I don't get reflections off my monitor, the wall, etc. When our cat stays out all night, he invariably comes in and sleeps for hours, even in the summer. We suppose he doesn't sleep while outside because he must constantly be aware of his surroundings. In an open office environment, I feel like our cat.
Move your computer so you can see people and have a flat surface behind you.