If, as a paid-up near-geriatric, I can make an observation based on a lot of personal experience: it’s not about saying no, or denying your sexuality, or having as much pleasure as your body craves. It’s about the selection process up-front, so that when you end up naked with another person you both feel good about being there together. Sometimes (as in my case) this can require a major re-thinking about who we tend to attract by default, the signals we may be giving out, our style of socialization, and so forth. For me, there’s never such a thing as too much (or too varied) sex even at my advanced age (four times per day, for about an hour at a time, is ideal even now); but there is such a thing as people who aren’t compatible with who I am as a person.