The Monster in My Closet

From Wil Wheaton's blog:

About two hours ago, I thought to myself, "'There's a monster in my closet' would be a neat way to start out one of those scary short stories I loved to read when I was in middle school."

I wrote it down, then wrote a little more and a little more. Right around the time I realized I had no idea how it ended, the ending tapped me on the shoulder and said "boo!"