Psion
Adventurer
There are things in my campaign world that even I don't know. 
The first colonists on the island that the PCs are currently on disappeared for unknown reasons. The colony wasn't re-established until 100 years later. Nobody knows why. I haven't decided.
Likewise, there was once a race of altruistic wizardly humans that inhabited the current campaign continent over 1500 years before the current game time. The conflict that devastated their empire is known. But there were survivors of that conflict -- they were eventually victorious. What is not known is what happened to the survivors. Another thing I haven't decided.
The game world will be played by many players over the years. I don't feel uncomfortable not deciding the immediate answer to a mystery, as it is something that I may use in a later group even if I am not interested in exploring it right now.

The first colonists on the island that the PCs are currently on disappeared for unknown reasons. The colony wasn't re-established until 100 years later. Nobody knows why. I haven't decided.
Likewise, there was once a race of altruistic wizardly humans that inhabited the current campaign continent over 1500 years before the current game time. The conflict that devastated their empire is known. But there were survivors of that conflict -- they were eventually victorious. What is not known is what happened to the survivors. Another thing I haven't decided.
The game world will be played by many players over the years. I don't feel uncomfortable not deciding the immediate answer to a mystery, as it is something that I may use in a later group even if I am not interested in exploring it right now.