A monster nightmare

Question for you to answer: Why am I always getting nightmares?
Last night I got another nightmare. This time, the nightmare story is mixed from all the nightmares that I've got before... So one day I was riding my bicycle in front of my house. Suddenly I saw a robot with 3 heads approaching. I cycled as fast as I can to avoid it but thanks a lot to a tiny black rock, I fell. I tried to run away using my bicycle again but I can't it was broken. So I hid behind a small hut and I saw the robot looking for me. BTW the robot had red eyes and sharp teeth and claws. When I knew that the robot will sneak into my hiding place, I moved backwards but when I moved backwards, I just realized that it was a dead end. But I found this small hole that I can go through, so I went through it. Still, the robot found me. So I ran and ran until I saw my friend a BLUE WHALE (I am not joking ok! It was in my nightmare!)
So I asked permission from my friend to slide down his body because I was in a rush. So he lets me. When I slid down I saw a cave that will lead me somewhere safe but when I was only one step from the 'EXIT', the blue whales' tail fell on top of the exit and shocked me because I almost got hit by his tail. Then everything became blurry and that was the end. And in the end, if I am not mistaken, I saw myself safe somewhere I don't know.
Now can you please try to answer my question that I placed above? PLEASE!!! :P