Chicken Or Egg?

I have come to realize that I don't like to sleep alone.
Not that I can't sleep alone in a bed - goodness knows I would never sleep at all if that were the case because when Tarzan is in the throes of a new computer game there is no such thing as sleep for him and I just can't function that way - but I don't like to be alone in the house.
I'm not sure if it's because I never have...
I am the oldest of nine children. There was never a night in my eighteen years at home where I ever slept alone in the house. Then I went to college and had roommates for five years. With one or two exceptions - like all nighters in the studio - they were always home to sleep, sometimes more often then I. After college, I lived in a boarding house type deal for the summer and I was alone in my room all the time, but never alone in the house. Then Tarzan and I got married and he's always been there. Thankfully neither one of us has to travel a lot because I wouldn't survive.

...Or if I never have because I don't like to...
A drunk guy wandered into our house one night when I was a kid - no one locked the door in that neighborhood in The Frozen North; people might die if a freak summer blizzard took them unawares and they couldn't find shelter - and I awoke to the sound of my mother calling frantically for my father. I am much like my father in that we are not morning people and neither of us wakes up well. I distinctly remember the grumbling, inaudible sound of my father herding this guy out the door and then stumbling back to bed. He barely even remembered the event the next morning, but I lay awake the rest of the night, freaking at every little noise.
Then, in college, my roommate left the sliding door to the patio unlocked one night and some guy came in and then into my room. I was asleep and I don't remember much; only rolling over in bed, feeling something duck towards the floor, rolling over and poking him in the shoulder and asking what he was doing. He freaked, and ran out, which then woke me up the rest of the way. We reported it to security and the police but I didn't have my glasses on and he had his hood up so there wasn't much of a description.
...and when the cat woke me up in the middle of the night Wednesday and I was all alone in the house - my Thursday volunteer situation, you recall, has me at our house on Wednesdays so I can be on time while Tarzan stays with GOM - I couldn't go back to sleep, twitching at every noise - like the cat walking across the papers on Tarzan's desk - and I began to wonder why I was so weirded out by being alone in the night. It wasn't just our neighborhood because when Tarzan had jury duty and he stayed at our house and I was with GOM I had a similar freak-out. Lesser degree because GOM was downstairs but he wouldn't be much help if some weirdo climbed the tree in the front yard and came in the wonderful balcony that runs the front of the house. These are the things that run through my mind in the middle of the night when I am all alone in the house.
Thoughts?

This is me, wondering if I ever got over being scared of the dark.