The Happiness Code

You can't rely on a dupe filter, especially since many sites (e.g. medium.com, signalvnoise) tack phony fragment identifiers onto URLs to evade dupe checks.

Ideally, people would check before submitting; for example, search for a unique-ish keyword, sorting by date with newest first:

https://hn.algolia.com/?query=Happiness&sort=byDate&prefix&p...

That way, you can see if it was already posted.

The reason that dupes are bad is that any commentary is fragmented across distinct threads; a reader of one thread will generally not know the others exist, and those opportunities to enhance understanding are wasted.