When, exactly, does Luke learn about his father? By that, I don't mean the reveal in ESB about Vader being his father. I mean, when does he learn that his father was a Jedi Knight?
I was watching Ep. IV again with my son last night, and it occurred to me that Luke doesn't so much as flinch when Obi Wan mentions that he was a Jedi Knight alongside his father. So, it stands to reason that he already knew this. But how? Who told him? When? And what other information did he have about him? His name?