The challenge of his retirement Clough considered to be the controlling of his drinking habits, which had led to some strange moments and explanations. Being found asleep once, in a ditch, he said, was the result of having felt tired mid-ramble. He acknowledged his alcoholism after collapsing and being taken to a clinic at the end of 1996; in his autobiography Walking on Water (2002) he admitted: "I was spending time drinking when I should have been doing other things. It was bound to take over. If you do something to excess, something has to suffer somewhere." In January last year, he had a liver transplant, after doctors warned him that he had no more than two months to live.