This comes close to embodying the true sense of my actual nightmares (I consider the popular conception of "nightmare" to just be a fun thrilling dream). For me, zombies and monsters aren't scary. You can try to find a shotgun or at least hide. But something like "I soup ate a word dog" which makes no sense... YOU CANNOT RUN FROM IT. It seeps into your thoughts effortlessly and doesn't fit and mold of rationalism that you can make sense of. It is true terror manifested.