Do you have music playing when you make love? I hope you do so let's assume you do. Do you notice that you like to put on the same play list, over and over, at least some of the time? The one you remember having the best lovemaking to?
Very recent studies indicate that in addition to the regular nerves we have buried in our skin there are some new types that have been discovered...They are purely pleasure fibers and have a direct route to the brain.