I have to confess that until recently I knew nothing about sperm donation. Like many others, I suspect, I had no idea there was a crisis in donor numbers and, I guess, if I thought about sperm donation at all, it was as something a little bit seedy and embarrassing.
But then I met people like Siaran West, from Cardiff, who had been devastated when her husband's multiple sclerosis prevented them from having a child. Thanks to a sperm donor, they now have a lovely little girl.
I asked Siaran what she would say to anyone who was thinking of donating and she said, "I'd have to point at my daughter and say I'm just so incredibly grateful to whoever donated their sperm to help me have a child... when it can make that much difference, you just think that's got to be a fantastic thing to do."
Sperm donation literally gives the gift of life and as donor numbers have dried up, fewer and fewer people are receiving that gift.
So what has gone wrong? Well, the crisis seems to stem from the government's decision in 2005 to abolish the right of all sperm donors to remain anonymous. All men who registered as a donor after 1 April that year could have their identity revealed to the children created from their sperm when they turned 18.
The cliched image of the sperm donor has always been the medical student who filled a few pots in exchange for beer money. But what seemed like an easy way to help childless couples and earn some extra cash suddenly became less enticing at the prospect of up to 50 children (your sperm can be used by a maximum of 10 families) tracking you down and knocking on your door in the year 2023.
Clearly, something had to be done. So I undertook a mission to try to end the sperm crisis by not only raising awareness around the country, but actually asking men to come forward and donate as a pledge of support.
I decided to start with Labour MPs. After all, it was the government's change in the law that had led to this apparently disastrous shortage.
I made a list of MPs who fulfilled the donor criteria - male (that was crucial) and aged between 18 and 45. Armed with this, I headed to the Houses of Parliament in my mobile donation centre (a converted polling booth).
But, to my disappointment, the people who had stripped men of their right to anonymity were very keen to keep their own. I stood outside Parliament for hours trying to grab MPs to talk to, but no-one was willing to discuss sperm with me.
Undaunted, I booked a van and set off on a national sperm tour that would take in London, Oxford, Cardiff, Manchester, Newcastle, Carlisle, Edinburgh and Belfast. It was Belfast that shocked me most. The crisis is most acute here since, in the whole of Northern Ireland, there wasn't a single donor - not one.
Mechanics of donating
I went wherever men could be found - football matches, pubs, gay bars, fire stations, even a coalmine and a male voice choir. Everywhere I travelled, I was shocked by the confusion and lack of knowledge about donation and the law.
Others were worried about the mechanics of donation - one even thought he'd have to have sex with a woman who wasn't his wife - leading to understandable concerns.
Almost all the men were unaware of the need for donors.
But one thing is clear - it's not their fault that there is a crisis. A large number of those I spoke to were prepared to donate and genuinely wanted to help. One guy in Northern Ireland was so moved he decided to help - by becoming the first Northern Irish donor in decades.
"I put myself in their shoes," he said. "I thought what if I was that guy, what would I do? I don't want to be the one saying yeah, I'd love to have a sperm donor to help my wife have kids, but I'm not willing to give my sperm. It would be like if I needed blood but never thought about giving blood."
Other men were equally eager to give. The trouble was most of them wanted to do it anonymously.
The law was introduced to protect the rights of the unborn child and is supported by organisations such as Barnardos and the Children's Society.
Lack of funding
But with the drop in donor numbers I was keen to put some questions to the government: why, for example, they weren't organising a clear and focussed campaign to educate men about sperm donation.
"Where UK clinics have focused on modernising their services to attract donors - for example, realistic clinic opening times, they are recruiting identifiable donors."
But my research found most clinics are simply too under-funded to run a successful campaign to recruit donors, or to extend their opening hours.
The government also claimed a recent rise in donor numbers. Indeed, the latest official figures do show an increase... of 15. Yes, 15 whole donors.
The small increase is thanks to recent media coverage of the issue. But it's what economists refer to as Dead Cat Theory: a slight rise in numbers doesn't necessarily indicate a return to glowing health - even a dead cat will bounce when you drop it.
What these figures don't reveal is that donor numbers dropped massively in the late 1990s. In 1995 there were 418 sperm donors in the UK. Today, it's 265. And only 208 of these donors are based here - more than a fifth of donors currently supplying UK clinics are overseas.
In a country of over 22 million men, only a measly 200 want to donate. Fertility experts estimate that we need 500-600 donors for the current demand to be met.
Now, who made me such an expert on this you might be asking. Well, I admit, I'm not a politician and I'm not a fertility expert - I'm just an ordinary bloke, but it's ordinary blokes like me and the blokes who read this and watch the programme I've made for the BBC who need to be convinced to part with their sperm if we are to solve this crisis. I suppose there's just one final question that I haven't answered: did I donate myself? Well, you'll have to watch the programme to find out.
Mischief: The Great Sperm Crisis is on BBC Three at 2100BST on Thursday 17 May