Love is relative. Happiness is relative. Life itself is relative. What makes me happy isn't what's going to make you happy - or it might be, but I won't know of it. Considering, I've always been irked by people who tell me "You don't have such-and-such? You must be so unhappy!"
I get that a lot about relationships, for instance. I'm single, and I'm happy. Is that so much of a shock?
So, no. I don't believe in that concept of the "better half", OP. I believe we meet people and, well, if we're lucky, there's someone in there we'll like enough to, well, love, and that we'll want to spend weeks, months, years and decades nerding out with.
Not that this level of luck happens to everyone, and not that this denotes some sort of mean, average "Happiness Factor".
Real Life isn't The Sims 3. I don't need to keep my little "Social" meter filled; I can just base myself off of what I feel and when I feel like being around other people.