Only in My Dreams

I keep having this recurring dream where I can't get my sliding glass door locked.

Now, usually this wouldn't be something that is scarey. The dream scenarios vary.
Sometimes I can't get the door locked and there is some guy trying to get in, and I never get the door locked in time.

Other times, I close it, and forget to check and see if it's locked, and I go to bed. Only to wake up later with some guy standing over my bed looking down on me.

And yet other times, I try to lock the door millions of times, and the lock doesn't take. Finally, it lockes, and I go to bed. Only to wake up later, get up to check it, and it's unlocked.

I can't remember for sure, but I feel like I used to have this dream when I lived in some apartments when I was in High School. I either had these dreams, or you really couldn't lock the glass door at that place. I remember that I used to put in a metal bar whenever I was home alone, and my parents would try to come in the glass door after a night out, only to be extremely angered by my putting in the bar. But hey! At least I was a kid trying to be safe!

Either way, I'd really like to stop having this dream. Any thoughts? Can you stop yourself from dreaming certain dreams or am I helpless?