First, let's talk about unrealistic expectations. We know that about 20% of the U.S. population will not marry, and that of the 80% that do about half will divorce. Of the 40% that remain married, we all know that some are just plain miserable or complacent, so in reality maybe just half feel like they are with their "soulmate." Essentially then, you have about a 20% chance of finding a great match for a life partner-- so what about the rest of us? It seems to me that the numbers plainly indicate that odds are more in your favor if you apply your energy and effort to developing a great network of friends than putting all your eggs in one basket.
Second, when you convince yourself that someone is your "soulmate" I fear that you run the risk of ignoring red flags. You may make excuses for his/her bad behavior rather than try to address issues or see problems for what they really are, such as severe character flaws or true deal-breakers for you. If you think the person is "the one" you may stay in an unhealthy relationship simply because you think it is your destiny, when in fact we create our own fate.
Finally, if things don't work out or your partner dies, you will be devastated if you are convinced there is no one else out there for you. A much healthier outlook is to see relationships as serving a purpose during a certain point in time, but knowing that few actually last a lifetime. Just as we continue to evolve, so do our needs and wants in our relationships, and as this happens sometimes we may find we no longer align with our partner. But luckily the world is full of people with different ideas, values and interests, and part of what makes life so interesting is getting to share our experiences and learn from others.
So what if the odds are slim of finding a soulmate? As long as you are connecting with others and having fun, I think you are doing just fine-- along with about 80% of us, which puts you in really good company, and there the odds are quite in your favor.