I only recently remembered that Dooku was originally meant to be one of 20 Jedi that had left the Jedi Order. I'm aware that they were meant to represent ALL of the Jedi that had ever left the Order, so most, if not all, of the others were probably dead by the time of the events of the prequels. You never know. Could be something interesting to explore. I always wondered who the other 19 were, and what became of them.