In chemistry, there are atoms and molecules. Atoms have no will, no desire, no thought, no soul. Molecules are formed when atoms join together in a sort of mathematical precision, due to their natures. That is, when certain atoms come into proximity to each other, they will attract to each other, or repel away, and that’s just how it is. There’s not really any choice in the matter.
In this sense, we have soul mates. There is nothing romantic about this attraction, except perhaps as a sort of smokescreen created somewhere within the mind as a way of imposing meaning upon the relationship.
People have soul mates, gobs and gobs of them. All over the place. And these soul mates could be anyone, in any kind of rationally-understood relationship. Like, maybe the UPS person comes to the door, and you know, instantly, if you’re attuned to this stuff, that there’s a real bond that transcends all human understanding, in the way that covalent bonding transcends the ‘understanding’ of any atom that succumbs to it. You meet the UPS person, they meet you, and maybe you both hear the echo of something larger and more important somewhere up the chain, but there’s no human way to act upon it. So you sign for the package, and that’s that. Or maybe you exchange names, or maybe you even decide it’s all about romance, or who knows. But none of that is really altogether very important. The ‘soul mating’ happened already, and all that’s happening subsequently is your human form trying to understand it.
Does *that* answer your question? 
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Update: OK, more.
buttermelon comments, in part:
We actually have the power to break that chain — of being attracted to the familiar. The question may be – are we able to identify negative patterns and have the will and energy to do something about it?
I can’t tell you what the ‘soul mating’ actually is. I can’t comment on that, because, like I said: It’s way beyond and out there, and happening in a mysterious reality. The main point I’m trying to make is that ‘soul mates’ can be the most mundane relationships possible. You could see someone on the street once, and then never again in your entire life, and that’s a soul mate and the entirety of your relationship might have been meeting eyes for half a second. We bounce off each other like atoms and molecules. We form, disintegrate, reform, and so on, until we’re dead, and maybe even afterwards. Who knows? The ‘soul mating’ is something that we might feel or think or see, something that *seems* meaningful, but might not actually *be* meaningful, something that compels us, seemingly without reason or meaning. So we make it meaningful.
If we’re self-aware, and maybe somewhat detached from ourselves, we say, “There’s something special about that UPS delivery person.. I can’t quite put my finger on it… What’s the deal? Am I sexually attracted? Is there some kind of romantic love here? No matter how I approach it, I don’t understand it, but there it is..” If we’re not self-aware at all, we say “I LOVE YOU! YOU’RE MY SOULMATE! MARRY ME!”
There’s no chain to break. It just *is.* How we subsequently try to understand it is based on psychology and all that stuff about being attracted to the familiar and so forth.
In short: It’s a mystery. Explanations fall short, but that doesn’t keep us from applying and using them. We fall into relationship (and not just romantic ones), and it’s like waking up to find yourself sitting at the bottom of one of those spiral slides on the playground. Did I climb up to the top and slide down this thing? Because I don’t remember doing that… How can I try to understand?
