Writing is a challenging thing. There are always a million other things to do. There are always a thousand reasons not to.
I may not be any good.I don’t have time. So-and-so thought that this was a bad idea. Oh, but what if I’m terrible at spelling? I never took creative writing in school. I don’t have a degree in literature.
Ignore all that. Sit down, and pen the idea- or type it. I don’t care how, just do it. You are good enough, your ideas are worthy, and screw so-and-so. All that other stuff doesn’t matter. Writers come from all walks of life, and in a rainbow of colors. If you have the desire to write, and the ability is there, the other stuff can be taught. Grammar can be corrected. But there is only one you, nobody else will do what you can.
Stop making excuses, and write you darn book. Go on, right now. Do it!