It shows related discussions for each submission page. Many times, I found myself intrigued by interesting discussions which left me hungry for more and I'd go down a rabbit hole, or maybe it was promising but didn't get enough attention and I'd need to check if there were any related discussions in the past about the same subject.

I found that even though HN is a news aggregator, many discussions on HN are timeless (just like this here).

I'm proud of it and find the experience and flow to be very enjoyable. It also helps me find great stories that I might not have stumbled across.