Just about everyone has some sort of book in them. You may excel at some sort of creative art and want to teach others. You may have profound realizations that changed your life and you want to share them with others. You may want to inspire people to do their best in the workplace, or the home, or in nature. So...big question...what is stopping you?
Now, two people I've spoken with in the last year had been "working" on a book for literally years. They'd get motivated and write or edit, then run out of steam. Why? Usually fear. In fact one person actually told me she had no desire to be noticed - I have to wonder, then, why publish? What's fascinating about that case is that, close to the end of our process, she became very angry about the fact that low resolution images could not be used in her self-published book, and quit her process entirely. I know that her fear created an "excuse" for her to not step out and be known. I hope she was able to resolve that, as her topic was a really good one.
Two clients have worked with me to assemble wonderful blog posts into a book. The writing is already done! Just a matter of patchwork to get it all to flow. One self-published a paperback, and the other created an e-book for download.
One former client is a career search expert - and I mean expert! She worked hard to assemble her best systems for success into a book, and she has the marketing knowledge to really make a go of it. How exciting!
Bottom line: If you feel inspired to share knowledge with others, do not let fear hold you back. There is a reason you felt inspired: someone needs to know or understand what you have to say. Write! Just WRITE! Get it all out on paper, then organize and see what can come of it. You can do this!