Dubious Canonicity

Player investment in the story of the campaign is all well and good, but it can cross the line into fanwanking, especially if the DM is a little too liberal with mysteries. If you’re not sure about what’s going on it’s easy to fill in the gaps and make assumptions that are not entirely factual.

As a DM this is annoying. But it’s even more annoying when the player’s idea is better.