Hemar himself stated that before the outbreak of World War II he had already written 1,200 songs,[1] including such widely popular hits as Może kiedyś innym razem (Maybe Some Other Time) and Upić się warto (Let's get drunk).

He studied medicine and philosophy at the Jan Kazimierz University locally, and took part in the Defense of Lwów in 1918 and 1919 as a volunteer on the Polish side of the Polish–Ukrainian War of independence.

He was a key figure in the productions of Banda, Morskie Oko, and Cyrulik Warszawski ("Barber of Warsaw") cabarets; as well as the author of hundreds of Polish Radio sketches.

[2] His unhappy love affair with the Warsaw diseuse Maria Modzelewska inspired many of his songs including Chciałabym, a boję się (Happy Days Are Here Again, aka I'd Love To Do It, but I'm Afraid)[3] Soon after the outbreak of World War II Hemar fled Warsaw after being searched for by the Gestapo and reached Romania, and eventually the Middle East, where he signed up and served in the Polish Independent Carpathian Rifle Brigade.

For 16 years (1953-1969) he prepared and presented weekly cabaret programmes for Radio Free Europe, in which - in prose and verse - he commented upon all the important news from post-war Poland.