Something that bothered me in Jedi was when Obi-wan knew that Leia was Luke's sister, while apparently forgetting this fact in Empire. The book discusses the "other" on page 70. Kasdan suggests that Ben doesn't know about Luke's sister, but Lucas says that he does indeed, it's just that "He discounts women because he is a male chauvinist pig." I'm guessing that he is kind of joking, and he further explains this inconsistency by saying that Ben wasn't thinking. I explained this inconsistency by considering that the Jedi was a very patriarchal order, and the Jedi didn't consider that women could be Jedi (kind of like some other religious orders today). But looking at the prequels, and the fact that there are women who are Jedi, it seems completely absurd that Ben didn't set up any plan to train Leia, and didn't try to train Luke until he was nineteen.
Lucas's idea of the Jedi in ROTJ was much different than in the prequels, and I think much more interesting. I get the feeling that there was a warrior class and a priest or guru class, and only the warriors were called Jedi. These were doctrinally male, and to become Jedi they were trained by the gurus or priests in the ways of the Force, inheriting lightsabers from their fathers. The knowledge to construct lightsabers was lost long ago, so there's an ever dwindling number of them, and they are rare and highly prized possessions. I really wish Lucas had stuck with this idea through the prequels.