If there's one phrase I'd love to get rid of, it's "grow a pair". You hear it a lot nowadays, not just said by men to other men they wish would grow up, but even from men to women, or women to other women. "Grow a pair", they say, or "strap on a pair", as if a couple of testicles will solve all problems, like a pair of dangly amulets.

As most men know, growing a pair of balls, or having them drop, doesn't really change much at all. You remain pretty much the person you used to be, albeit with a slightly deeper voice. But still, in our culture and language, "balls" and "ballsy" mean courage or courageous; we talk of "cojones" or "having big balls" to mean audacity or power.

It's irritating nonsense, for several reasons. Courage isn't inherently a masculine quality, of course, but there's more to it than that. People often use the phrase "grow a pair" or "strap on a pair" as a way of belittling someone who has shown weakness, or vulnerability - someone who didn't show the requisite assertiveness that apparently lives in the testes.

As well as that, it reinforces the very worst stereotypes of the "man's man": the rush to confrontation, rather than negotiation; a certain headstrong or even bloody-minded quality; the idea of maleness as something that is aggressive, rather than collaborative.

For those of us men who are more team players than the all-conquering alphas we're supposed to aspire to be, it's a tiresome thing. Not all of us are meant to shout and bellow and fight our way to success; some of us prefer other ways of doing things. It's not through a lack of balls, but through a lack of unfeeling uber-competitiveness.

Must we still, in this new century, be talking of men as people who should be nasty, assertive, pushy, unpleasant, in order to be proper men? We're not all Gordon Ramsay (who has a fondness bordering on obsession for talk of "big bollocks" when upbraiding some poor cookery sap on television).

But there's something else, too. The real quality that testicles have is staring us in the face. Human males, unlike many other mammals, have external testicles, dangling merrily away from their undercarriage like a couple of lychees in an old leather purse.

This evolutionary quirk exposes the adult male to extremes of pain and suffering at a stroke. A well aimed kick from an attacker, or punch from a young child (children happen to be at the perfect height to connect with full force), and even the toughest man will be reduced to a quivering foetal position of helplessness. There are no words for the pain, which I am pretty sure is definitely entirely worse than childbirth (THIS IS A JOKE).

How humans could ever have believed that a benign (and in many cultures apparently male) creator decided to place a couple of pain grenades hanging invitingly down as they do is a question for anthropologists. What it means, though, is that men's testicles, far from being a centre of our strength, are our most visible sign of weakness.

Every year, dozens of men die because they decided to "strap on a pair" rather than admit their own weakness. Whether it's shrugging off a niggling illness or feeling unable to talk about mental health problems (young men are at far greater risk from suicide than women, for example), the things we've been told about what it is to be a man can be our own worst enemy. It's not weakness to admit you can't cope; it's strength.

If we can't get rid of the odious phrase "strap on a pair" perhaps it's time it should take on a new meaning. Because it is courageous to strap on a pair - to hang your vulnerability so obviously, to invite a kick in the balls. It's an aspect of masculinity that often gets overlooked, the quality of honesty, vulnerability, and gaining strength through admitting your weaknesses rather than glossing over them with displays of machismo.

So if someone asks me to strap on a pair, I'll take their advice: be more aware of shortcomings; realise how vulnerable we all are; remember that a fall from hubris is just a well-aimed punch in the nuts away. That's real courage, I think.