Significant moments in writing

Last night, I tweeted that I got to an important sentence in my novel:  "I wish I had a face."  It was the sort of moment I've been waiting for in the last week or so of writing, which has been going painfully slow.  I've reached a new point of direction, where my characters have started telling me what they want. The novel I'm working on is about the future AI civil rights movement, and features, among other things, a sort of machine called a homunculus, which amounts to a robot body designed to house AIs that grew personalities organically on the internet.

In the beginning, a homunculus is a vessel designed only by the most obscure computer fanatics, where most people don't even really acknowledge that AI exists.  But, if things continue to go the direction I have in mind, over the course of the novel, homunculi will become more personlike, at times skating the border of uncanny valley, and making them a much more intense focus of prejudice.

I knew all this in the abstract, but it's nice, now, to have a more specific handle on how it's going to play out in the story.