First, the scientific reason:
As you may know, falling in love involves feelings of exhilaration, intense passion, and euphoria, especially if the loved one reciprocates the passion. Of course, if the loved one doesn’t feel the same way, these feelings morph into desperation and heartbreak. But let’s not go there today.
Back to falling in love. Our energy skyrockets, we have heightened powers of concentration and persistent thoughts about the object of our affection. During this state, our brains show heightened activity in areas that are rich in dopamine if scanned using functional magnetic resonance imaging (fMRI).