I don't believe in "The One" or "soulmates". I think we just find someone that we get along reasonably well with and work together on the rest.
IMHO, I find the belief in the concept of "The One" rather dangerous. The relationship between partners will always take work. As soon as people decide "this person is 'The One'", what's implied is: "okay, I don't have to work at it anymore, it should be self-sustaining from now on".
Which is the beginning of the end.
Getting along so well with someone that you can't imagine being in a long-term relationship with anyone else is great. I don't dispute that.
But firstly, I wish people would understand that a marriage is so much more than a long-term relationship.
Secondly, you also need to be able to "NOT get along" well together... applying mathematical precedence, it's ((not (get along)) well). Obviously, if you're (not ((getting along) well)), then there's no point. But ((getting along) well) AND ((not (getting along)) well) is essential for a marital relationship.
In English: you need to be able to vehemently disagree, fight like cats and dogs and even HATE each other. And still be able to resolve that. And still love each other. And be committed to your partnership and life together. Outside of abuse, there can't be any more dealbreakers.