Lack of interest with 知ったことか The expression 知ったことか implies a lack of interest in a thing. “I have nothing to do with it.” Examples Don't care if it troubles you with 知ったことか 三ツ星カラーズ » Volume 1 » Page 138 Nothing to do with Ayumu's situation with 知ったことか それでも歩は寄せてくる » Volume 2 » Page 97