There's always something right behind you at all times. Never more than a few inches away from your skin, sometimes close enough that you can feel the prickling on your back. If you look behind you you can't see it, because it'll always be behind you no matter where you're looking. It doesn't want to hurt you, however. It merely wants to observe. You may feel it sometimes, the crawling anxiety or unease, but don't be alarmed by this feeling. Instead welcome this entity warmly and learn to become comfortable with the fact that you will never be alone. It's looking over my shoulder right now as I type this, I can feel it. It will always feel a bit uneasy when it gets close. But I've learned to see it as a friend, and you should too.