I don't remember when I learned the rules--I was probably 8 or 9--but I played extensively in 5th grade. We had probably 30 minutes of free time from when we got to school to when it actually started, and we often played chess. I probably was the most knowledgeable about the game--I had a computer program that taught some basic strategy--but I had a disturbing penchant for bonehead moves, which leveled the field somewhat. None of us studied the game intensively--as evidenced by some of the openings my opponents used, which I will charitably call "unorthodox"--but it was a lot of fun. After 5th grade I played very rarely, probably once every couple years. The tournament was a nice way to get back in it a little, and I was pleasantly surprised by my showing.