What is the biggest obstacle that’s keeping you from writing a book?

My good friend Mathew Burdette always wanted to write a book but was too afraid to do so, due to fear of rejection or failure, but was thrilled to know that I the host was a writer and had published several books. This inspired Mathew, so he advised me, that he would someday write and publish a book. It has been about two years now, and Mathew contacted me on Facebook and told me, that he finished his new book, which was published on Amazon.