The Unbearable Lightness of Being

Human life occurs only once, and the reason we cannot determine which of our decisions are good and which bad is that in a given situation we can make only one decision; we are not granted a second, third, or fourth life in which to compare various decisions.
—  The Unbearable Lightness of Being, Milan Kundera

And again he thought the thought we already know: Human life occurs only once, and the reason we cannot determine which of our decisions are good and which bad is that in a given situation we can only make one decision; we are not granted a second, third or fourth life in which to compare various decisions.‘ 

- Milan Kundera in The Unbearable Lightness of Being