From A Film I Like.

There is a difference between needing or liking something and [i]wanting[/i] something. There's no contradiction here. In any case, you have to take everything David says with a big pinch of salt. He's sneaky, like that.

Yes, David is a sneaky little devil! He is a machine, so does he 'want' to be free, or 'imagine' what it would be like? I am not sure. Freedom may be the situation he would define as the best logical situation for him to thrive. In the film, we see David manipulating people & his environment until he is free from any & all controlling forces over him. Once free, he can follow his own will, but I am not sure what one would actually call his driving inner force?

Agree with Blue and zz above. Remember towards the end that David says 'Don't all children want their parents dead?' I believe that David does want to be free and in spite of him being synthetic seems entirely more human than given credit for. I suspect he can experience anxiety based upon survival protocols, and even awe like he displayed when the Prometheus first arrived at the target threshold. BTW it is worth checking out Lawrence of Arabia to gather background for Prometheus. That line and also 'Big things have small beginnings.' come from that film. Weyland also seems to be a fan of T.E. Lawrence.

What if a different movie was being watched by David? Alien perhaps,,

weylands also a fan of neitzche 'thus spake zarathustra' which says alot about his take on morality, maybe he was brought up by zoroastrians he was born in india so its possible.