Soul Mates

Are we supposed to let go of the past? I know we're supposed to learn from the past, and I think I've done well at that. What about people from the past? If we learn from them, and our experiences with them, are we supposed to let them go? What if we can't, even though we need to? Then what? What do any of you think about the whole "soul mate" theory? Do you think we all have one, or more than one? I'm pissed off at myself, and I'm just trying to talk this out. Alright, gotta feed Rosie, I'll continue this later...