The first time I heard the expression "soulmate" used by a friend, it was by a twenty-something Canadian woman who began an online relationship with an American in his late teens, moved to live with him, got pregnant, tried working illegally in the US, and eventually (I think) got married. This rather turned me off to the term. This didn't sound, to me, like someone pursuing their "soulmate"; it sounded like two people doing something terribly stupid and permanent because they didn't want to take the time to think through the consequences.
The popular idea of a soulmate, I think, has too much predestination wrapped up into it. It implies that each person has a member of the opposite sex somewhere in the world (but, miraculously, almost always within a few miles of where they're living) with whom they share a spiritual psychic link that means they're cosmically intended to spend the rest of their lives making each other happy.
This is good for fairy tales and popular fiction, but it's a bad way to approach romance. It means that there's one and only one person anywhere on the planet that you can be happy with, which is silly. It means that you'll be eternally joyful together while you're alive, which is wrong. And it means that each person and their soulmate are linked in some ephemeral fashion that gives them a perfect and complete understanding of each other, which is ridiculous. I've never even heard of a longtime-married couple who thought that their relationship was an embodiment of perfect understanding and communication and happiness.
The reality is that true soulmates are made, not born. Couples come together because they have shared interests and goals in life, and they build up from there. Communication is practiced. Understanding is developed. And the joy of being with each other fades an grows, fades and grows with each day that the two people are together. There's an initial illusion of magic because, let's face it, it takes most people years to find just one person who shares even fifty percent of their interests. But that's just statistics, not spirituality.
Am I being cynical? No, I'm not. I'm recently married to a woman with whom I intend to spend the rest of my life. When we first met, I wasn't looking for a relationship and she was already in one, but she noticed me and remembered me well enough to pick me out of a hundred other e-mails eighteen months later. After just a couple of conversations, we were sure we had the same goals and essential interests; after a few months of dating and talking, we were certain of it.
But there's no supernatural magic in this, romantic though it may be. We have a lot of trouble communicating with each other some days. We've been nasty to each other a couple of times when the day hasn't gone as well as we'd have liked. Stresses have come and gone. But we're still committed to each other because we want to be, not because we think we were fated. Because if you're not willing to work at a relationship, all the fate in the universe isn't going to keep you together.