[1] Jensen started writing for music magazines when he was 15, and The Sydney Morning Herald employed him as a critic when he was 16.
After finishing high school, the Herald took him on as a news reporter, a role he was in for five years, until at the age of 23 he became summer editor at the paper.
[3][1] In 2008, Archibald Prize-winning artist Adam Cullen asked Jensen to live with him and write his biography.
He stayed for about four years, in the role of observer as Cullen dealt in drugs and was arraigned for weapons possession.
[4] He later said "...I allowed myself to be in fairly traumatic settings during that book, because I had convinced myself that the professional response was to be absent from them" and that he "[needed] to continue working on the project to properly extricate [himself] from it".