It's German and it's a Typo, maybe autocorrect. I meant Jet Lag, which is also used in German as Jetlag. But I somehow thought it's written Jet Lack and typoe

It's German and it's a Typo, maybe autocorrect. I meant Jet Lag, which is also used in German as Jetlag. But I somehow thought it's written Jet Lack and typoed it as yet lack. No idea why I thought it's Lack, maybe because you lack sleep after taking a jet ?