Romantic love is a drive — a basic mating drive, not the sex drive. The sex drive gets you out there for a whole range of partners. Romantic love enables you to focus your mating energy on just one at a time, conserve your mating energy and start the mating process with a single individual.
What sums it up best is something that is said by Plato over 2000 years ago. He said the God of love lives in the state of need. It is a need. It is an urge. It is a homeostatic imbalance. Like hunger and thirst, it’s almost impossible to stamp out… Love is in us. It’s deeply embedded in the brain. Our challenge is to understand each other.