Why do I only feel "In Love" with my boyfriend based on my current mood?

First off...sorry but i think these signs are HOCUS POCUS. But secondly....i dont think its right to like someone based only on "FEELINGS". That is why i think people get into trouble. If you dont have legitimit reasons that you can explain to anyone asking you than its a FEELING based relationship only. If everyone did that we would all be cheating on eachother with someone all the time. our emotions are always changing as humans and that shouldnt be the determining factor as to why we like our significant other. There should be reasons understood in our hearts as to why it is we like that person. Qualities which help to define that person. For example: someone who loves to help you clean your house, wash the dishes, has a love for God, Loves his mom & dad. Things like that. Things that will bleed into your relationship.Positive things. It shouldnt be "aww he makes me feel good about myself." or "he loves the same music as i do!" or "hes always giving me compliments." these are things that can easily dissapear when its too late. Like you get pregnant or married. I dunno. Just my thoughts and hope it helps. Good luck.