Einmal ist keinmal

The German proverb einmal ist keinmal means "once doesn't count" (literally "once is never"), used to say that a single event is not significant or that one can be forgiven the first time one makes a mistake (but, implicitly, not the second time).

It is used as the title of an East German film released in 1955.

The saying is also employed in the novel The Unbearable Lightness of Being, by Milan Kundera, where it is glossed with the statement that "If we only have one life to live, we might as well not have lived at all."

In 2012, it was used as the title of the German release of the American movie One for the Money.