Full Idea
The destiny of men is designed for happy moments (every life has those), but not for happy eras.
Gist of Idea
We can only achieve happy moments, not happy eras
Source
Friedrich Nietzsche (Human, All Too Human [1878], 471)
Book Reference
Nietzsche,Friedrich: 'Human, All Too Human', ed/tr. Faber,Marion [Penguin 1994], p.222
A Reaction
The vicissitudes of life (my favourite word!) are such that even the most serene and well-adjusted person is going to be perturbed on several days of the week, even if only by the unhappiness of the people around them.