WHY DO PEOPLE KEEP BELIEVING IN THE ILLUSION OF LOVE?

Sure its a deep emotional, attachment to someone, but in the bigger picture, What does it mean, and who really benefits from the idealism of love? Soul-mates say they fell in love, it was love at first sight, and so on- why do they need name tags, why do they need definitions? why are there other factors that determine compatibility? Logically, it's much more efficient to get together, after weighing differences and similarities- with the differences outweighing the similarities, because that makes for a more interesting connection, but also, if the things you can't stand, outweigh the the things you can, then, that should be a logical point of separation. People don't hang around through miserable relationships for no reason- its probably interesting, the idea of conflict, and they need it to fill a void, placed by boredom, or some other feeling, which they outweighed to be more or less favorable to them. You can't know you're a perfect match, or as those lovers coldly put it- soul-mates- until you've met every single person on the planet, and - no one has met every single person on the planet- and therefore, the idea of soul-mates seems a bit faulty- I believe the term is syllogism-All dogs are animals- All animals have 4 legs, therefore all dogs have 4 legs- you get my point....Just because someone says you're their soul-mate, doesn't actually male you soul-mates.