Originally posted by: auraloffalwaffle

In his early conversations with Luke Skywalker, he evaded discussion of Princess Leia until late after key facts were told in Kenobi's presence. When Obi-Wan began to tell Luke a tale about Anakin and the Jedi, Threepio requested to be shut down, likely to avoid discussion and facing awkward memories about his Maker's tragic fate. Nevertheless the supposedly inert droid was only pretending unconsciousness; as he eavesdropped on the conversation he swayed slightly but visibly. This evasive behaviour was prompted by Threepio's recognition of Anakin's lightsabre.

Uh-huh...

Yeah, I can field this one.

It's a man. Pretending to be a robot. And he's in a suit. And he can't stay perfectly still.

Sometimes the best answer is the easiest answer.