We tend to measure our enjoyment of sex in terms of performance.
But sexual happiness isn't measured by how much sex you're having, how long you're having it for or how many people you've had sex with.
Sexual happiness is an attitude: a healthy, uninhibited way of thinking about sex that gives you the courage to be truly yourself sexually.
There are many light bulb moments that bring us to this blissful state - which is why the following list is by no means exhaustive.
But, for me, these are cornerstones of the sexual happiness philosophy.
YOU KNOW YOU'RE SEXUALLY HAPPY WHEN....
You like your body. It's impossible to achieve sexual happiness if you don't like how you look. Being sexually happy means making peace with yourself: embracing the bits you like and accepting the bits you don't.
You know your body. You know which parts love being touched a certain way and what's never going to work for you even if the rest of the world seems to get off on it.
You've decided for yourself whether hook-up apps like Tinder work for you and don't give a toss what anyone else thinks about that decision.
You don't feel paranoid if your fantasies are sometimes odd. You know most fantasies don't represent our real desires so don't unnecessarily over-analyse.
You're able to be sexually happy without a partner. You have fingers and sex toys and lube and an imagination that's free to wander wherever it wants, to keep you sexually satisfied during solo sex sessions.
You understand and enjoy the differences between you and your partner rather than try to turn them into sexual mini-me's.
Thinking about sex makes you feel happy not anxious. You've sorted out any past sexual problems so you can have stress-free sex now.
You don't over-react if you go through a low or no sex period but know not to ignore it either. Sex 'droughts' are normal at some stages but warning signs in others.
You're brave and adventurous and try new things rather than stick with the tried-and-true to end up stuck in the inevitable sex rut.
You're happy trying new and potentially embarrassing things with a partner and trust that both of you will instinctively know when it's OK to giggle and when it so isn't.
You're generous with sex and make sure you're good at it. Enthusiasm counts but good technique is crucial long term.
You don't compare how much sex you're having in a long-term relationship with couples who are still at the ten-shags-a-day-still-isn't-enough stage.
You touch each other affectionately and sexually and both know the difference so sexual signals are clear.
You both know honesty isn't always the best policy. To be 100 per cent honest, you'd have to express every fleeting sexual thought you have about other and every negative thing you think about your partner. Neither is wise or kind. Tact beats honesty hands down.
You've found a partner who is the right fit libido wise. You don't feel hassled to have sex and don't feel like a sex pest when you initiate.
You're able to suggest something quite out there and are confident your partner isn't going to look at you like you've suddenly grown an extra head. If they do, you consider it their problem not yours.
You can turn yourself on and don't expect your partner to take that responsibility every time.
You talk about and solve sex problems as they happen rather than let niggly little things turn into big bedroom monsters.
You make your own rules. You're unique, so is your partner and your relationship. People like me can rattle on all they want but only you two know what works best for you.
Tracey Cox's sex toy range is available from lovehoney.co.uk, the sexual happiness people.Suggest a correction