If you could tell your mum anything at all, what would it be? It’s a massive question and one that's hard to answer off the top of your head. Actor and author Samuel Johnson – who first burst onto our screens in The Secret Life of Us, before winning the hearts of Australia with his charity work with his sister Connie, Love Your Sister – has asked some of the biggest names in the country that very question. They’ve written a letter to their mum in his new book Dear Mum, and he joins us to talk about what he would say to his late mum and why his older sister is the mother figure he didn't have.