Let's get something straight: the concept of finding one's soul mate is merely an (unscientific) mathematical problem.
Take the roughly 6 billion human beings on the planet. Divide that by two for your preferred gender (and don't give me a hard time about bisexuals or actual statistics -- just hang with me!).
Now there are three billion people to choose from. Let's say you are very particular and you typically are attracted to only 1 in 5,000 people. That still leaves 6 million. Considering, time, geography, financial resources and other limitations, let's reduce your opportunity to truly know all of these by a huge amount. If you had access to meeting only 10% of those people, there would still be 600,000 people who you would like.
Subtract "can't get past the looks" issues, annoying habits, and all other factors that become dealbreakers. Half of the contestants are gone. Now there are 300,000 people, all of whom you could like. How many could you love? How many could you find to be truly compatible?
For all the bad rap on people, there happens to still exist untold numbers of them who are fabulous, amazing, world changing and attractive. If you had the chance to know even a fraction of your remaining population, do you truly believe you could love only one?
Both in my personal experience and within my psychotherapy practice I have found that many people expect their primary relationship to provide more than their partner has to give. This is not a bad thing, it's just that it's contrary to the fairy tales that ruined us.
To determine your true compatibility with your chosen soul mate, ask yourself if you share common goals and values. These are the things that last long after hair is falling out of his ears or her mustache has matured. Is this a person who you respect? Are there enough meaningful things to tolerate your partner's mere humanity? This imperative process involves accepting that either some of your needs will have to be fulfilled elsewhere or -- God forbid for Fairy-Tale-Entitled-Dreamers -- you might contemplate surviving without some perceived desire!! Who says we have to have 'everything' we can imagine we need or want in order to thrive?
If you are already partnered, reevaluate your relationship accordingly. If you are looking, try to understand what you can do to create opportunities to meet the thousands of people with whom -- under the right circumstances and synchronicity -- you could call, "soul mate."