To me, the idea that fun and "serious discussion"/work are mututally exclusive is the biggest disappointment of the HN culture. And it's just not true!

For me, if it's not fun, it's not worth doing:

http://www.inc.com/magazine/20081101/how-hard-could-it-be-th... -- For his part, Jeff says he didn't want our new venture to feel "like work" -- that if Stack Overflow wasn't fun to do, he didn't want to be doing it. If I had tried to make him play by my rules, I don't think the project would have come together, at least not as well as it has. --

Good work is fun, almost by definition. And that should come across in your comments about the work, too.