You will never get to the irreducible definition of anything because you will never be able to explain why you want to explain, and so on. The system will gobble itself up.
As you work, the mood grows on you. There are certain images which suddenly get hold of me and I really want to do them. But it's true to say that the excitement and possibilities are in the working and obviously can only come in the working.
I approach every part I'm asked to do and decide to do from exactly the same angle: who is this person, what does he want, how does he attempt to get it, and what happens to him when he doesn't get it, or if he does?