As with all things felt, we describe them based on other similar things we feel. You say food is "rich" when it gives you the same feeling that you have been told by others in the past that they are rich. You know the feeling of liking something, and when you like something a lot, you are told that is love. Media will warn you that love can boil over into obsession, but there is no way to feel that difference. It is a determination made by others from the outside. So much like agony is an extreme pain, love is an extreme like. And there is absolutely no way to know if you are "experiencing it" or not.