Some day, some random gamer is going to stumble across this thread and read your hard-earned words of wisdom. It could be an brash, iconoclastic story gamer or a die-hard traditionalist. It could be someone with thirty years of playing and designing experience or a young kid excited and nervous about the first ever game of D&D he's about to run for his equally clueless and excited buddies. It could be a historian from hundreds of years in the future trying to grok our quaint and baffling rituals by actually playing the silly things. You'll never know.
So what have you learned that you absolutely have to share with this unknown seeker of gaming knowledge?