After finishing high school, Leak trained for two years, 1974-1975 at the Julian Ashton Art School, dropping out before his studies were completed. He also spent time working as a postman. In the late 1970s, Leak departed Australia on an art pilgrimage to Europe. In 1978, he was particularly impressed by an exhibition of the paintings of Paul Cézanne at the Grand Palais in Paris. While in Salzburg that same year, Leak met a woman named Astrid and they married soon after. The couple lived together in Bavaria until 1982, when they relocated to Australia. They divorced in the early 1990s.