"I dreamt myself away," says Houben, now 46, who was misdiagnosed as being in a persistent vegetative state after a car crash.
Doctors and nurses in Zolder deemed him a hopeless case whereby his consciousness was considered "extinct".
The former martial arts enthusiast and engineering student was paralysed after a car crash in 1983. He was finally correctly diagnosed three years ago and his case has just come to light in a scientific paper released by the man who "saved" him.
Doctors treating him regularly examined him using the worldwide Glasgow Coma Scale which judges a patient according to eye, verbal and motor responses.
During every examination he was graded incorrectly. And so he suffered in silence, unable to communicate to his parents, his carers or the friends who came to his bedside that he was awake and aware at all times what was happening in his room.
Only the re-evaluation of his case at the University of Liege brought to light that Houben was only paralysed all these years. Hi-tech scans showed his brain was still functioning almost completely normally.
Therapy has now enabled him to tap out messages on a computer screen and he has a special device above his bed enabling him to read books while lying down.
When he woke up after the accident he had lost control of his body, "I screamed, but there was nothing to hear," he says.
"I became a witness to my own suffering as doctors and nurses tried to speak with me until they gave up all hope.
"I shall never forget the day when they discovered what was truly wrong with me – it was my second birth. All that time I just literally dreamed of a better life. Frustration is too small a word to describe what I felt."
The neurologist Steven Laureys who led the re-examination of Houben, published a study two months ago claiming vegetative state diagnosed patients are often misdiagnosed.
"Anyone who bears the stamp of 'unconscious' just one time hardly ever gets rid of it again," he said.
He said: "In Germany alone each year some 100,000 people suffer from severe traumatic brain injury. About 20,000 are followed by a coma of three weeks or longer. Some of them die, others regain health. But an estimated 3000 to 5000 people a year, remain trapped in an intermediate stage: they go on living without ever come back again."
Houbens remains in constant care at a facility near Brussels.