After reading Book 6, I believed the theory that Snape was in love with Lily, and he joined Dumbledore's side against Voldemort because he was so horrified when his actions caused her death. I also believed that he killed Dumbledore ONLY because Dumbledore begged him to (knowing that if Snape didn't, he'd die for breaking the unbreakable vow).

In one of the interviews on leakycauldron.com, Jo Rowling hinted that someone else was present when Voldemort killed James and Lily Potter. When I read that, my guess was that it was Snape.

However, in Book 5, Snape's worst memory (the one he hid in the pensieve, and that Harry saw) wasn't witnessing James and Lily's death, being threatened by Voldemort, or anything else like that. It was the bullying incident with James and friends.

If he truly had been in love with Lily, wouldn't you think that either seeing her death or learning of it would have been his worst memory? And wouldn't you think he would have hid it in the pensieve so Harry wouldn't learn of it?

Definitely some good questions and points. I hadn't heard that someone else had been present at their deaths. Wow! I too believe that Snape had a "thing" for Lily even though he called her "mudblood" when she tried to help him.....
Is it time for book 7 to come out? :laugh: