What do you most fear?

"Don't write what you know. Write what you fear," a famous writer once said. (I think it was Stephen King, but don't hold me to it.)

That bit of advice has been on my mind of late. Over the years I've been plagued over by some recurring nightmares. I'm talking gnarly, bad-ass, they-should-put-me-on-a-couch dreams. I'm wondering if I should consider mining a few of them for writing material.

Assuming one can calibrate a Fear Factor by analyzing dreams,  here are some of my worst fears:

1. The sun starts to act strangely in the sky and then blows up, casting the earth into freezing darkness.

2. I'm trapped on an alien planet, being attacked by the locals. I am required to  a) fight the aliens while b) figure out how to get back to Earth.

3. I'm being attacked by a grizzly bear, but a pack of dogs shows up and helps me fend it off.

4. I'm being chased by a guy with a gun. I somehow find a gun, turn and fire, only to have the gun misfire. Sometimes the dream ends on a more optimistic note, and I manage to beat him senseless with a handy object.

5. I have to land a plane after the pilot dies.

Based on these dreams, it sounds like I should be writing an episode of V, Airport, or the Dog Whisperer.

Maybe it's real-life fears that should inform one's writing, not dream-fears. Here are some things I'm actually afraid of in real life:

1. Losing a loved one or friend. That's got to be everyone's top fear.

2. Walking into a spider's web. I have nothing particular against spiders--I'm just terrified by the prospect of one going for a ride-along in my hair.

3. Being hit by a tsunami (never mind that I live on top of a hill).

4. Being hit by a home-invasion robbery.

5. Having to land a plane after the pilot dies. (Dreams and reality are in agreement on this one. Maybe I should consider flying lessons.)

I have in fact mined a few of these fears in my fiction. I've had a home invasion-style assault in one book.  Fear itself even becomes a character trait in the series. One of my characters drives his daughter crazy with constant warnings about all the possible bad things that could happen to her.

Do you mine your fears in your fiction? What are some ways your personal fears manifest themselves in your stories?