Martin Kemp's brain tumour surgery left him dyslexic - and feeling like a "train wreck".
Despite the Spandau Ballet bassist, 64, making a complete recovery following an operation to remove two cancerous growths in 1995, he now struggles with reading as words at the end of sentences become muddled.
During a frank discussion on Wednesday night's episode of ITV's I'm A Celebrity...Get Me Out Of Here!, Martin told his fella campmates: "I'm dyslexic. I struggle with reading."
Comedian Ruby Wax, 72, and television personality Jack Osbourne, 40, questioned whether the Gold star opts for audiobooks instead, which Martin confirmed he does not.
Martin discovered he had a brain tumour after appearing in a Canadian production, portraying a professor, and needed to visit the makeup department to have a bald cap fitted.
When the hair and makeup team applied it, they discovered a bump on the rear of Martin's head.
The former EastEnders star added: "I could hear the whole of the make-up wagon go quiet because you could see this lump on the back of my head. But it was skull, it was bone. So it stretched out.
"And what it was, the tumour that was underneath it, that had been there for about 12 years, had run out of space to grow in the little gap, so it started to grow into the skull, into the bone. So it started to show itself as a lump.
"And within two days, I was back home having my head cut open."
During the procedure, doctors discovered an additional tumour beneath the larger one. The concealed growth could have proved fatal for Martin.
He explained: "The one in the middle was the dangerous one.
"So they cut this one out, and they zapped me with stereotactic radiation."
When fellow presenter Kelly Brook enquired whether Martin had "lost memory or anything", he said: "For a while I lost everything, I couldn't walk, I couldn't see in one eye.
"I was a train wreck afterwards. Now I have a few little bits and pieces, and one of them is dyslexia."
Ruby said: "So you didn't have dyslexia beforehand?".
Martin responded: "No."
Discussing how the experience affected his loved ones, Martin said: "It was tough. It wasn't just tough for me, it was tough for everyone around me. You know, mum and dad were still around then, my brother [Gary Kemp] and my wife [Shirlie Kemp], it's a terrifying thing to watch someone go through that.
"One minute, I was fitter and healthier than I've ever been in my life, next minute, I was in a mess. It was like being in a car crash. I thought I was dying, and it was a tough one."
In a private moment, Martin reflected: "It took me a long time to recover. Your body and everything about you wants you to get back to normal. You want to get back to people not feeling sorry for you because you were sick.
"But does it give you a new perspective? It does for a short while, but not forever."
He told his jungle companions: "It was a test."