The Cellar - The Worst Nightmare

I think this fits, so I'll go ahead and write about it.

The worst nightmare I had was also the simplest.

It was dark. Pitch black. I couldn't see anything, but there was a sound... almost like a heart beating. Getting louder, and louder, and louder, and louder... boom. Boom. BOOM. <b>BOOM</b>.

I woke up terrified and soaking wet with sweat. I went into my mom's room and she said I was the most pale she'd ever seen me.

I'll never forget it. Not really an image, I guess. But an imagined scenario, if you will, from my own mind. I've never had it since (I was about 11 at the time), and I hope I never do again.