Okay here's a question to ponder. Why is it that nobody in the prequel trilogy calls Count Dooku "Darth Tyranus", except for that one scene at the end of AOTC when Sidious refers to him by his Sith title? I know that to the masses, he's just Count Dooku, but obviously General Grievous knows of his Sith title, since Sidious talks to Grievous about the death of his apprentice in ROTS. So why is it that even Grievous just calls him Dooku?