At the age of 50 Graeme Simsion did what many of us only dream of: he ditched the business world to become a writer. A decade on, and the now 62-year-old is a literary sensation, selling more than 5 million copies of his Rosie novels. The books, whose protagonist, Don Tillman, is on the autism spectrum, have also made the author something of a hero in the autistic community.

You wouldn’t expect a book about someone with autism to be booze-soaked. But Graeme Simsion’s Rosie novels are just that. By Simsion’s own admission, Don Tillman is a borderline alcoholic. And I wonder, as I make my way to the restaurant to meet Simsion for lunch, whether I have a boozy afternoon ahead of me.