Sometimes I /will/ post or comment, but because I don't go back to my post or comment, I rarely see how people respond. Sometimes, when I'm bored I'll click through my submitted posts/comments and be surprised at how others responded to my submissions (usually it's a positive reaction ).
How do you use HN? How do you keep engaged in discussions? In my mind I just assume people either keep on hitting refresh or use some other third-party tool to help them see responses from others.