In the beginning of our love lives, it is the beastly instinct of sexual attraction that drives us all. The butterflies in your stomach simply signal your mind that the person in front of you would make a fantastic mate to make babies with. Without this primeval drive, you won’t ever fall for anyone in your entire lifetime. The very attraction you feel towards a person in a romantic way, is a mental manifestation of a subconscious desire to mate with that person.