I learned that you shouldn't type something that you wouldn't be willing to say to someone's face, that stuff on the internet is not fact all the time, and people sometimes say things without thinking about who may read it or who they may offend. Just by reading! Also, I really like giant gourami and clown loaches.
I have learned a ton about fish, but mostly that I don't know jack about them. I think someone said above about being a dumb person who is a MFKer, thats how I feel some times. This for the most part is a great place to hang out, good people, and I even get to laugh every now and then when I see people try to link to photos on their hard drives.