It's true. There is also some interesting gamification in looking at your Karma and trying to figure out why it increased. Sometimes my karma randomly goes up

It's true. There is also some interesting gamification in looking at your Karma and trying to figure out why it increased. Sometimes my karma randomly goes up a bit, and in investigating why, I get to go back and re-enjoy threads on articles because someone replied to something from a while ago, but most of all I like the impetuous is on me to go look for replies, I think it adds a level of friction that makes the HN experience better.