Because of their shared passion for the operas of Richard Wagner, they quickly became close friends and later roommates in Vienna while both sought admission into college.

As the only son of a self-employed upholsterer, Kubizek was expected to someday take over his father's business, but he secretly harboured dreams of becoming a conductor.

He was later offered a position at the Stadttheater in Klagenfurt,[8] but this job and his musical career were cut short by the beginning of World War I.

After seeing Hitler on the front page of the Münchner Illustrierte (circa 1920), Kubizek followed his friend's career with some interest, although he did not attempt to contact him until 1933 when he wrote to congratulate him on having become Chancellor of Germany.

"[9] When the tide began to turn against Hitler, Kubizek, who had avoided politics all his life, became a member of the Nazi Party in 1942 as a gesture of loyalty to his friend.

[6] In December 1945, Kubizek gathered the collection of keepsakes given to him by Hitler during their youth and concealed them carefully in the basement of his house in Eferding.

In the epilogue, Kubizek wrote, "Even though I, a fundamentally unpolitical individual, had always kept aloof from the political events of the period which ended forever in 1945, nevertheless no power on earth could compel me to deny my friendship with Adolf Hitler."

Kubizek's second wife and widow, Pauline (1906–2001), was credited with having provided the Stocker Verlag with additional photographs for the book's fourth edition in 1975.