Tsk... human nature.
If you tell people something's funny then some will make every effort to not laugh, and then make sure you know that they didn't find it funny in order to undermine you. If you had a different thread title then the response wouldn't have been the same.
It reminds me of people who go to see a good horror film determined not to get scared. Then they make sure they tell you they weren't scared in order to achieve an emotional victory.
I thought it was funny