I was looking through another thread and it sparked a thought in me. What if since these scientists have your brain and so much technology that they can access your memories before the shooting? It could explain why you meet Ulysses (and possibly Christine?). And maybe, for a reason I can't come up with, they make you relive them, which would explain how Ulysses would be friendly, seeing as he is loyal to a certain faction, because before the shooting you wouldn't have any reputation with any of them. It would also explain why Christine has her voice. I remember a speech option with Veronica that makes it seems like you have previous opinions of the Brotherhood of Steel. Since in the trailer has Christine's voice actor talking about the BoS, that may be how you get your previous thoughts on them.

Post your thoughts on this theory, and add or debunk it if you like.

Shouldn't this be in said thread?

It wasn't very related to the exact thread.