Comfort Zones

My bedroom is a shed located in my backyard about ten meters from the house. Ever night, I travel between my house and room at least 3 times and when I'm out in the open between both rooms, I feel a sense of fear, as though someone is hiding in my backyard ready to come attack me. But once I get inside my room, that feeling instantly disappears and I feel like no one can get me even though my door is never locked and my backyard is easy to get into from the street.
I believe we can feel this way when we're alone to. For example; it's lunch time at school and you just left your classroom. You have no idea where your friends are so you walk through the school yard pretending to be knowing where to go but really you're just examining every area in sight to see your mates. You feel as though everyone is staring at you so you pull out your mobile phone and pretend to text or cruise through Facebook. you feel uncomfortable; but then you find your friends and instantly that feeling of 'everyone is staring at me' just disappears.
I am regularly wondering why we feel this way. Could it be because we feel like we are shadowed in our friends presence and secure in our own rooms. Or is it really because that's just where we're most comfortable and used to so it's just natural.
Blogs suck after a while. Rawr. this sucks.