Writing a book doesn't have to be hard. The process is simple and repeatable.
You don't have to spend years agonizing over the words, editing 20 drafts, producing this century's greatest masterpiece.
You DO have to sit down and work at it. Every day. You can dispel any romantic ideas you have about living the writer's lifestyle. The fame, the relaxation, just write for an hour a day and then go sit on your hammock.
Writing is a grind, and you have to keep coming back to it, no matter how crappy you feel. Pages don't write themselves.