Moderation is one of the keys to enjoying your life and having magic in your relationships.
The law of Decreasing Marginal Utility is one of the basic laws in economics. When applied to us, it implies that the additional pleasure derived from each repetition of any activity is less than that derived from the previous repetition. To put it simply, if you have a bag of chocolates to eat, the additional pleasure that you get from eating each chocolate is likely to be less than that from eating the previous chocolate. The pleasure keeps decreasing till you stop enjoying the chocolates. If you were to continue eating, you might actually start disliking chocolates, and eventually throw away the bag
This is true for most things in our life, be it watching movies, traveling, reading, partying, eating out or socializing. If you really want to enjoy these activities, do them in moderation, and give sufficient gaps in between repetitions. Even in your relationships, the magic would last forever if you give each other time away from each other.