I was also confused by some of these early dialogues where it seemed my character knew about his past, but I didn't. When the Exile was asked about the past, I had two kinds of dialogue options: the very specific 'Ah, yes, I was at Malachor 5' response that your character seems very confident about, even though I've never heard of Malachor 5; or, 'I don't remember much about it', true for me, but seems to be a lie for my character. I hope that made sense.
Looking back on it, I think the writers were doing something pretty interesting and innovative. I've never known a game that gave you so much control over the back story, both in terms of the Revan m/f/ds/ls options and your freedom to establish the Exile's motivation in following Revan. At the beginning, and later with Atris, and in the holo-recreation of your trial, you are in control. It beats the alternative, of having to sit through a long, fixed backstory.
First time through, I probably worried too much. Every time I've replayed, I've really appreciated the freedom to role play the Exile as I wish.
<{POST_SNAPBACK}>
the handmaiden does have a motive to join your party, she was instructed to by atris