Former Wales striker John Hartson believed he had cancer for four years before he finally got the illness diagnosed.
The 34-year-old last summer underwent extensive surgery an chemotherapy after testicular cancer spread to his lungs and brain.
Hartson was not surprised by the diagnosis.
“I actually knew it would be cancer, I had this feeling in my gut,” he told the Daily Mail.
“I had a lump on my testicles for around four years and so I had this picture in my head. It was of me walking into a doctor’s room, or a hospital, and them telling me exactly what I heard in Swansea. I foresaw it.”
Asked why he did not see a doctor earlier, he said: “It was just me being stupid, and boyish, and not mature enough to face it. I hoped it would just disappear, but the lump got larger.”
He continued: “I had two brain operations and was in intensive care. I got pneumonia and I apparently stopped breathing at one stage, but they brought me back and I had pipes and tubes coming out of me, connected to a ventilator.
“For a month they were just trying to keep me alive rather than tackle the cancer.”
Hartson, who played for Celtic, Arsenal, West Ham and Coventry in his career as well as earning 51 caps for Wales, believes the illness has forced him to grow up.
“It took me a long time but, finally, I’ve matured,” he said. “It took a couple of marriages, four kids and illness, but I’ve grown up.
“I’ve now set up The John Hartson Foundation in the hope I can help other young men avoid the same mistakes.
“Ryan Giggs and Martin Johnson are trustees and I think we can make a difference. If I’d heard someone like me talking four years ago I would’ve gone to the doctor straight away.”
The former West Ham player revealed his training ground bust-up with then team-mate Eyal Berkovic, when he kicked the Israeli in the face, still haunts him.
“The Eyal Berkovic incident really blighted my career,” he said. “It’s something I deeply regret. Eyal is a terrific fella and he made a lot of my goals at West Ham.
“I get asked about it all the time, even though it happened 12 years ago. But when you do something that thuggish you rightly get a reputation. I’ve got a big heart. But when you do something that vicious you carry a reputation.”
Hartson faces further surgery on his lungs and to clear out debris in his brain.