text: First I'd have to examine the similarities. They are all, most likely, what was once simply the instinct to procreate.  \n\nThese words are symbols like all words, the concepts they represent to us are broad and almost undefinable.  For instance, there are many different "flavors" of love.  This really means that the word "love" actually covers many different concepts that have similarities but are not identical (brotherly love, a mother's love, romantic love).  Likewise when one is "infatuated" with a new band, it means something quite different from when one is "infatuated" with a person.\n\nHow they have become different would perhaps be related to the varying stages of a romantic relationship.   At first there is lust, it is strongly driven by hormones making it feel like raw primal desire.  If you continue to see the person you may become infatuated with them, meaning that thinking about the person consumes most of your attention, all day.  This phase is terribly distracting, every other second you find the person popping into your head.  Finally, if you keep spending time with the person you may develop love, a deep caring for their wellbeing and an emotional attachment that would hurt you if it were broken.  At this point it becomes more similar to familiar love like a mother and child, but retains a certain amount of lustiness and infatuation.  In a good relationship, the partners both work to keep love, infatuation and lust strong.