If anyone, from reasoning, exclaims loudly that victory of Zeus,
Then they have acquired an understanding of all these things;
Of he who guided mortals to reason,
Who laid down that this possesses authority:
'Learning from adversity'.

Even in sleep there trickles through the heart
The disabling recalling of the pain:
And wisdom arrives regardless of desire,
A favour from daimons
Who have taken the seats of honour, by force.
(Aeschylus: Agamemnon, translated by DW Myatt)