Whenever someone finds out I freelance write, they always have a book they have been working on. I know that everyone in any sort of business runs into this problem, but I find it very interesting how frequently people are writing books.
I guess I should not be surprised. It is very easy to begin a book. It is very hard to complete it. However, when you are working on someone else's book, you tend to be more inclined to finish the project so you can have instant gratification of getting paid. When you complete your own book you often then have to go through the heart rending difficulty of not finding a publisher (and mounds of rejection letters from publishers and agents alike) or you self-publish and do not make past 1,000,000,000 in sales rank on Amazon. Yeah, writing for yourself is tough and it goes beyond thick skin - it is more like turtle shell plated skin.
Although I like to be practical, this is my income. So, when people say, "I have this book I would like you to look at" I usually try to take a look at it and give them an estimate on what it would take for me to complete it. I also try to encourage them to self-publish.
Although it is difficult not seeing your book rise to number 1 in sales rank on Amazon, it is better than getting a rejection letter in my opinion.
Granted, when my HIV and AIDS: The Essential Guide made it to 100,000 twice, that was good enough for me - Radiotherapy and Chemotherapy: The Essential Guide will be coming out next.