One day a few weeks ago I didn't really intend to do much. I opened the document and wrote some notes at the end of the essay, after the Words Cited, without even bothering to find where they would go in the essay. I opened the document later in the day and fixed a few sentences, added a few more things, re-arranged elements of the argument. Every time my word-count increased by a few hundred words I quit and did something else. I was feeling extremely lazy.
My document, however, did not seem to care about how lazy I was. It still increased its length by 400 words, which is all it was asking. It may not have been my best work, but it will average out.