Putting it negatively, the myth of eternal return states that a life which disappears once and for all, which does not return, is like a shadow, without weight, dead in advance, and whether it was horrible, beautiful, or sublime, its horror, sublimity, and beauty mean nothing.

[....]

If the French Revolution were to recur eternally, French historians would be less proud of Robespierre. But because they deal with something that will not return, the bloody years of the Revolution have turned into mere words, theories, and discussions, have become lighter than feathers, frightening no one. There is an infinity of difference between a Robespierre who occurs only once in history and a Robespierre who eternally returns, chopping off French heads.

[....]

For how can we condemn something that is ephemeral, in transit? In the sunset of dissolution, everything is illuminated by the aura of nostalgia, even the guillotine.

- Kundera, from the first chapter of The Unbearable Lightness of Being; mistakes mine, typed hastily from my dead-tree copy for want of a quickly DuckDuckGoable digital one.

(yes, it goes on to wrestle with many of the objections/concerns you should already have about the small snippet above)

You inspired me to pick up that book again for this week. Thanks!