I really don't think there's any such thing as soulmates. I think the whole idea is just a reflection of this world's attitude that "you are who are and if people don't like that they can kiss you...
Shouldn't bother what? I'm not saying we're all 'destined' to be with someone but that there may be one person above all other people that you get along with.
It just seems to me that people who talk about "soulmates" aren't going to be satisfied with any relationship they enter into because there are always going to be changes they need to make to make ...
I can totally see how there are just so many things to deal with that it really is just another added worry to think about soulmates. On the other hand, it's a really nice thought if you think you have found your soul mate. You can just look at that person and be like "wow..despite the differences and all the work we still have to do to make this work, we're perfect for one another."