Good point. I suppose I can often figure out the meaning of my own dreams and nightmares, seeing as I know what's going on in my life etc.
For example, last night I dreamed of my brother being 2 of himself, and one cutting the head off the other and then trying to kill me. My Grandma was sleeping upstairs. I called the police and an abundance of them came in boats, were very unhelpful, and then peed on me before they left.
And in real life, my brother has recently been lying to me about his life, which means I am forced to see him as a person much different to what I thought he was. This would explain the one killing the other. Not sure why my Grandma was there, but I have had bad experiences with the police before so I guess thats where they came in.
I suppose normal people would just wake up and think 'oh, that was horrible' and not be scared for the rest of the day. Thats probably my mental illness not being able to deal with it!