How many words do you write per day?
I had not heard of Christopher before so when I read somewhere that he had written ten books in two years, I fully expected to see ten short stories.
Not at all!
I wrote a six hundred page book myself, but it took over a year. Christopher's are all considerably larger than the 'standard' two hundred and fifty.
Another impressive aspect is the variety of genre's.
I really must sit down and read a couple from cover to cover.