Our lives are influenced by our perceptions – including our sex lives. One of the most fascinating sex studies I have ever heard about involved showing how women’s sexual response can be improved (at least in the moment, not necessarily over the long term) by thinking positive thoughts about oneself as a sexual person. Try it – next time you are having sex and tough thoughts pop into your head about work, stress, family issues, how your partner hurt you once, how a former partner made you sad, whatever – try "switching channels" in your mind and telling yourself how good this feels, how much you like/love your partner, how nice it feels to touch and be touched. See if it changes anything for you.
On a related concept – but totally different note – take a look at this very Polyanna-ish remake trailer for The Shining and how happy they made it sound. Oh, the editing power of movie tools… and the editing power in our own minds to change our experience of sexuality.