Yes, for me planning has always been very difficult since projects always looked like impenetrable amorphous blobs. You have to really work to break them down into smaller properly sequenced steps. Luckily it seems like something you can learn. It always seemed like some people were just born planners and some (like me) were not, but now I think I am starting to penetrate the thicket. But I do still have a long way to go.
And what makes it really difficult for me is simultaneous scheduling with allowances for new work cropping up. I really like the thought from the book that you don't do projects, you do steps of a project.