In his latest novel, the Booker Prize-winning author imagines a dying megalomaniac billionaire – not based on anyone in particular, or so he says. Speaking to Nick Duerden , he reflects on his late-blooming success and how he holds on to hope amid the current ‘sickening’ state of his home I f happiness really does write white, then authors everywhere must be overjoyed in these oppressively dark days. The more dangerous the world becomes, and the more despotic its leaders (objectively insane,