The first time it happened I hated it.
At the end of one of The Hepatitis C Trust's support groups, a guy in his late thirties came up to the desk where I was working and asked if he could speak to me. I thought perhaps he was going to say how useful the group had been or ask if we could hold them at a more convenient time, something like that, something logistical.
Instead he said: "They took me off the transplant list this morning." Then he said: "Please will you help me?" He clearly believed there was a reasonable chance that I could help whereas I knew immediately that that was going to be near impossible.
People aren't taken off the waiting list for a new liver without a very good reason. It seemed ironic because I had set up The Trust in 2000 precisely because I had found it impossible to find support for myself, and here I was unable to do anything to help.
It turned out that Jim - that was his name - had been diagnosed with liver cancer brought on by his hep C. Initially he had two small tumours and was put on the list for a transplant, but a recent scan had shown he now had eighteen tumours and they told him there was nothing they could do. Livers are in such short supply and, because he already had so many tumours, the chances of them forming again on the new liver were so high that the hospital effectively sent him home to die.
I hated the feeling of impotence, knowing that there was nothing I could do, no hope I could offer him but knowing too that his death within a few months could easily have been prevented. He had to have been infected with hep C for at least 20 years given the progression of his liver disease, and if he had been diagnosed earlier he could have been offered a very good chance of a cure.
This is what tears at me in my dark moments. I am not doing enough. We are not doing enough, because Jim is not an isolated case. There are tens of thousands of people in the UK like him, living with hep C but not knowing.
For most people there are no symptoms until the liver disease it causes is very advanced. It's like a fire without smoke: you're asleep in the bedroom and you wake up to find the whole house ablaze and your chances of getting out alive all too slim.
We are not doing enough to diagnose these people. We are not even diagnosing enough to keep pace with new infections each year.
The UK is not unique in this, which is why the 193 countries that are members of the World Health Organisation decided in 2010 to make July 28th World Hepatitis Day, only the fourth disease-specific official awareness day (the others being for HIV/AIDS, TB and malaria). An awareness day, however official, is of course not the answer.
It won't find all those at risk - there are many more at risk than you could fit in the Olympic Stadium. It is not the answer but it is a start.
Charles Gore is the Chief Executive of The Hepatitis C Trust, a patient-run and patient-led UK charity that provides information, support and representation for all those affected by the disease. To find out more, visit www.hepctrust.org.uk