Doris Betts, my mentor, told me one day that you’re either innately a short story writer or a novelist. She didn’t mean one couldn’t be the other; she simply meant that one’s nature leaned toward either the short story or the novel.
I’ve quoted Lawrence Block below on the rigors of novel writing. I don’t necessarily agree to his analogies here, but he has given you the perspective of a novelist.
“Short-story writing, as I saw it, was estimable. One required skill and cleverness to carry it off. But to have written a novel was to have achieved something of substance. You could swing a short story on a cute idea backed up by a modicum of verbal agility. You could, when the creative juices were flowing, knock it off start-to-finish on a slow afternoon.
A novel, on the other hand, took real work. You had to spend months on the thing, fighting it out in the trenches, line by line and page by page and chapter by chapter. It had to have plot and characters of sufficient depth and complexity to support a structure of sixty or a hundred thousand words. It wasn’t an anecdote, or a finger exercise, or a trip to the moon on gossamer wings. It was a book.
The short-story writer, as I saw it, was a sprinter; he deserved praise to the extent that his stories were meritorious. But the novelist was a long-distant runner, and you don’t have to come in first in a marathon in order to deserve the plaudits of the crowd. It is enough merely to have finished on one’s feet.”
~ Lawrence Block, Writing a Novel, 1979 ~