On a related topic: Anyone want to sign up for a HN meet up in Hong Kong. I have read at least a few expats on HN said to be working in HK. Not sure if there are many more of us.
It happens to me as well. All the time. My explanation is that the brain feels rewarded when discovering a new interesting article. And in the age of information the addiction is so high, that when you get back to old articles, the brain does not get the high, so instead it seeks its dose back to the front page of HN. And this goes on and on. We are the mice on the information treadmill.