Inspiration is scary.
Perhaps you're trying to write in a new area (writing a book seems to frighten the wits out of many writers), or perhaps you're trying a new market. Whatever -- you're inspired by a project, but you're also scared of it.
Over time, as you continue to write, you become accustomed to dealing with fear. You learn that everything you write is written one word at a time, so you write one word, and the next, and the next, and before too many minutes have passed, your inspiration has crowded out the fear. You realize that being scared is natural. Your fear arises, and then it dissipates. If you pay too much attention to it, you'll never get anything done. :-)
If you're scared of a project, it doesn't mean that there's anything wrong with you. It doesn't mean that you should give up the project.
Inspiration may also scare you because you can't give yourself reasons for what you're inspired to do.
For example, in around 2001, I felt inspired to create a blog. At the time, blogging was new. It seemed like a colossal waste of time. So I ignored the impulse. It returned. I ignored it again... and it returned. So, feeling a little put upon and very annoyed, I gave in to the inspiration to blog... and I'm very glad I did. Blogging has done a lot for me, and I'm grateful.
Here's another example. In 2005 I gave in to impulse (inspiration) and decided to buy a Mac computer. This was illogical, because I write for PC magazines. What earthly use would a Mac be to me in the world of PCs? It turned out that buying the Mac was the best thing I ever did. My Mac made creating Web sites ridiculously easy. Using RapidWeaver, I could set up a site in hours, and that ability has made me a LOT of money since 2005. :-)
Here's the bottom line: as writers, we're creatives. We rely on our inspiration, and because inspiration comes out of left field it can be scary. If you follow your inspirations however, you'll reach many pots of gold. So when you're inspired, trust that inspiration.
