I've been roleplaying since I was about 13 years old and I had a few forums of my own starting around 16. First was a pokemon fan game project and then later I had roleplay boards. There were a lot of mistakes along the way, but I made some good friends and remember it fondly.

I quickly became known as the "evil dictator". I was a little too strict with rules and activity requirements, and a bit pushy demanding results and posts. Worked a little too hard to get things moving. Unfortunately, this took some of the fun out of it and I lost some members because of it. At least the few who stuck around with me were close and productive. Too bad life got in the way and I had to give up my forum. 

Another big mistake was trying to merge my real life with online life. Having IRL and internet friends on the same forum didn't work out so well. They formed cliques and eventually the forum died.