He was born in Prague as the third and youngest son of a Jewish father, Leo Popper, who was a travelling salesman, and a Czech Christian mother.

Both brothers and father survived Nazi imprisonment and returned home after the end of the World War.

He was an enthusiastic hockey player and played on the junior team of HC Sparta Praha, but his hopes for a professional ice-hockey career were dashed by a serious illness and tonsillectomy.

In 1949 his close friend Arnošt Lustig recommended that he concentrate on writing, and as a result, Popper was engaged as a sports reporter by Czechoslovak Radio.

During the 1964 Winter Olympics in Innsbruck he showed signs of the mental illness that would later end his official journalistic career.

As I was leading the cows and horses from the barn, the Austrian police arrived..."[6]Following this he was diagnosed with bipolar disorder.

Some of his works were adapted for the film: Zlatí úhoři (Golden Eels) (starring Vladimír Menšík) and Smrt krásných srnců.