Yes, indeed. Once you are clear on the lower horizons and in control, what's left is the scary part. David Allen said it directly "you can do anything but not everything."how much picking the right projects at the right time with the good synchronization with my above horizons is important.
I think it is helpful to see yourself distinct from your projects. Yes, your life's work is an important part of who you are, but you still are not your work. You do your work. You have feelings. You have thoughts. But you are not your work, feelings or thoughts. You are you. (And in my worldview at least that's enough. No need to proove something.)
You may have had a NA at the beginning stages of some project like "brainstorm 20 ideas for widget production." If you have well sorted SdMb lists, this brainstorming already happened.