Drnovsek served as prime minister from 1992 to 2002, after which he became president.
He did not run for a second term in elections late last year and was replaced by Danilo Turk in December.'New age guru'
After realising his illness was terminal, Drnovsek believed that he had cured himself by changing his diet, his lifestyle and his way of thinking.
After many years as a politician, Drnovsek turned into a "New ِِِِAge guru".
Watch Barnaby Phillips' interview with Janez Drnovsek
Drnovsek said: "It is hard for me to say if the change was only caused by the illness.
"It is true that the illness acts as a shock - it awakens one."
After his term in office, he moved from Ljubljana, the capital, to the remote village of Zaplana. Drnovsek considered a political career a "waste of time" and instead focused on helping the poor and weak.
Drnovsek was once pro-EU, but gradually grew critical of it. He was particularly angry with the organisation's agricultural subsidies, complaning that the EU "subsidises a cow each day with $2 - that's more than half the human population gets".