The story
- French · borrowed fromça ne fait rien“it doesn’t matter”
- English todaysan fairy ann
A homophonic translation of French ça ne fait rien (“it doesn’t matter”), probably originating among British and ANZAC army soldiers during World War I (1914–1918).
First known use, by meaning
- from early 20th c. It doesn't matter.
Etymology from Wiktionary, CC BY-SA 4.0.