No tree becomes rooted and sturdy unless many a wind assails it. For by its very tossing it tightens its grip and plants its roots more securely; the fragile trees are those that have grown in a sunny valley.

Seneca the Younger (c. 4 BC-AD 65) Roman statesman, philosopher, playwright [Lucius Annaeus Seneca]

Moral Essays, “On Providence,” 4.16 [tr. J. Basore (1928)]