But if you do it too much and want it all the time then it is an addiction and can be treated. Usually in your 30's you have more of a sex drive, but again I don't know if you are single or married. If you are single, you might not have enough stimulation sexually. If you are married, if you don't have things on your mind, you could have grudges or resentment towards your partner. You could fall in love at first sight or it could gradually creep up on you.
Love does have a balance of good and bad.
In the beginning in the honeymoon stage, you only see the good. Then you see the bad later on. In the beginning, you might only see the positive traits and later on you see the negative. If you are attracted to someone chemistry wise you see the imago. Imago is the unconscious composite image of the positive and negative traits of your parents or your relatives.