At the very end of a book I can manage to work for longer stretches but mostly making stuff up for three hours that's enough. I can't do any more. At the end of the day I might tinker with my morning's work and maybe write some again. But I think three hours is fine.
For my part if I consider poetry as an object I maintain that it is born of the necessity of adding a vocal sound (speech) to the hammering of the first tribal music.
