Love is when you are attracted to somebody through a mix of physical appearance, compatibility, and genetics. Then you feel a big stir of your hormones and desire to smurf that person, and when you do, you feel obligated to stick with them for years exclusively despite your body being made to move on and duplicate the feeling and smurfing with somebody else.
Or when Cupid shoots you with an arrow, but he only appears on Tuesdays of odd months of every other year in the Winter. He's rare.