I start out to write five days a week, and then it runs to six days and finally seven. Then, eventually, that wave of weariness overwhelms me and I don't know what's the matter. That is, I know but I won't admit it. I'm just tired from writing. As you get older, writing becomes harder. By that I mean you see so many more potentialities. Things like transition used to trouble me. But not any more. When I say it's harder, I'm not talking about facility. You learn all the so-called tricks, but then you don't want to use them.