In an interview with Cinescape George Lucas explains the complicated storytelling of his Star Wars films. You can read the complete article at Cinescape.
“Whenever you talk to an author and somebody that writes, they write this back-story, [and it’s] basically character driven,” Lucas said. “What you’re doing is setting up who your characters are. Obviously there are a lot of technical issues going on. I had to get somewhere. Okay, this is the father; these are the kids. Where the hell did they come from? In [PHANTOM MENACE], I was dealing with the beginning. I was dealing with a lot of issues a lot of fans didn’t want to hear about – symbiotic relationships and things. The public yawned and people weren’t ready for it when I said Anakin was basically created by the midichlorians, which is a spiritual, symbiotic idea. In that case I was talking much further back, indicative of all creation. At the same time, it is inevitable we would get to the love story. It is inevitable that, let’s face it – Padme is going to get pregnant.”
He added, “I knew when I made the film a lot of fans weren’t going to like this because I wasn’t making the movie they wanted. They wanted me to start with EPISODE II. They wanted to see Jedis fighting; they wanted to see battles. They wanted to see THE MATRIX. I knew that I was telling a story that I wrote 30 years ago and I had to start at the beginning and I had to do all the groundwork, which means you have to lay all the pipe for the world you are creating.”