Do your nightmares have a common element?

I have noticed a common theme for the nightmares I remember: they all involve some kind of issue with my teeth. Parasitic worms tunneling their way through my molars. My incisors falling out. My canines being riddled with cavities and the pain associated with them.

And on and on and on, for the vast majority of my life. I've only realized this theme for my nightmares recently, and it made me wonder what others have experienced.

What about you? Do your nightmares feature random subjects of fear? Or do your nightmares share a common story as well?