Nietzsche's 'eternal recurrence' is a thought experiment, not a belief

In Thus Spoke Zarathustra (1883), Nietzsche posed the question: if you had to live your life again, in every detail, infinitely many times — would you want to? He called this the 'heaviest burden', because it demands that you live each moment as though you would choose to repeat it forever. Nietzsche did not literally believe in eternal recurrence; he used it as a test of whether a person affirmed their life. The philosopher Albert Camus called it 'the most elevated philosophical thought' because it transforms the question of meaning from an abstract one into a practical one.

Source: Nietzsche, Thus Spoke Zarathustra (1883)