Gender inequality. It's a problem that's not going away; an inconvenient truth undermining claims of progress in 21st-century Britain and a persistent reminder of how far we have to go.
When I was younger I always believed that, in the workplace at least, the most effective solution was likely to come from women themselves. That the best thing to do would be for women to try to compete with their male colleagues, letting their equally impressive talents and abilities do the talking.
Over the course of my career, however, it's become apparent that this is not enough, certainly not for women in the City, in professions such as banking, consultancy or the legal world. The same is true for those in my own industry, advertising and media, where women are not being promoted enough or paid enough.
It's the elephant in boardrooms up and down the country: where are all the women? While boys' clubs may no longer rule, the truth is that women are routinely passed over for board positions. Despite all their hard work, prowess, qualifications and success, the right rewards are not coming their way.
There have been renewed efforts by business to tackle the issue, particularly at the higher levels of the establishment. Progress is certainly being made, with recently released figures showing that the UK's biggest companies are expected to meet targets set by Lord Davies of having a minimum 25% female representation at board level.
Casting a spotlight on the lack of diversity no doubt spurred action, but don't be fooled that the hard work is over. Much must be done to ensure that women are given a fair chance and to eliminate discrimination.
Not one FTSE 100 company can boast total gender parity in the boardroom. Indeed, research by the Guardian found there are more men called John running FTSE 100 companies than all the female bosses put together.
Cranfield International Centre for Women Leaders has estimated that women's representation on FTSE 100 boards is likely to stagnate when it hits 28%. Progress has been slower among the smaller listed companies that make up the FTSE 250 index, with women making up just 18% of boards. Across the whole spectrum of UK companies, the number is increasing, but we're still only at 14%.
There are many obstacles to overcome, but business must first accept the realities of the situation rather than drag its feet. I was a board director myself, recently stepping down as the co-global president and UK group chairman of Havas Worldwide to focus fully on One Young World, the global youth charity I founded in 2009 with David Jones. I've been lucky enough to work with some extraordinary women, with peerless talent that have deserved to be leaders in their field.
Yet time and again they have been routinely overlooked for the board positions they were due. No doubt many will claim there are other determining factors, but we're running out of excuses. It's nothing but discrimination - pure and simple.
So what can be done? First and foremost is for the broader business community to commit to meeting the targets set out by Lord Davies. This is the bare minimum. Every single CEO of a listed UK company should make a statement of intent and act on it. Paying lip service to gender equality isn't enough without action.
Part of this must include quotas that promote greater diversity at a boardroom level. Business, and society with it, would be better with women on boards, but as it is we're not getting a shout.
Until recently I've been against quotas - if you'd asked me 10 years ago then I'd have given you a different answer. I viewed them as artificial measures that were insufficient to stem the broader attitudinal bias. But I've come to view them as a necessary stepping stone to bringing about meaningful change.
I've no doubt that having more women on boards would lead to a trickledown effect throughout companies, which would grow to appreciate the benefits of amplifying the voice of women in business. Evidence suggests that companies with more female directors are also more likely to be socially responsible.
Which brings us on to the wider issue. Beyond the boardroom, sexism is rife. It's inevitable that most professional women will have faced problems at work simply due to their sex, whether that's through maternity leave or childcare.
Empowering women outside the boardroom is key to getting women into senior positions - and keeping them there.
Even in the UK, which boasts the fastest growing economy in the G7, gratuitous sexism is the biggest challenge facing working women today. We can't fix this on our own. We need men to recognise the problem, the scale of the epidemic, and the injustice of the situation.
Kate Robertson is co-founder of youth leadership forum One Young World and a former co-president of Havas Worldwide. Follow Kate on Twitter @kateatoyw