Australian's money trick to retire by 40

Every time Adelaide pilot Peter K bites into a mango, he feels happy and sad in equal parts. "Mum raised us alone - she was a single mum to me and my sisters," he explains. "As such, the grocery budget was really tight, and the only time mum could ever afford to buy a mango for us to eat was when they were heavily discounted, or at Christmas time. "These days, I have a large passive income that can afford me any grocery item I want, but I still pause before buying a mango, and it's still a big thing…