You have to write the book that wants to be written. And if the book will be too difficult for grown-ups, then you write it for children.
You can never be too rich or too thin
I couldn't hit an elephant's ass with a bull fiddle.
Luck? Sure. But only after long practice and only with the ability to think under pressure
To do easily what is difficult for others is the mark of talent. To do what is impossible for talent is the mark of genius.