Vernon Jones (1912)
200. THE ASS AND HIS MASTERS
A Gardener had an Ass which had a very hard time of it, what with scanty food, heavy loads, and constant beating. The Ass therefore begged Jupiter to take him away from the Gardener and hand him over to another master. So Jupiter sent Mercury to the Gardener to bid him sell the Ass to a Potter, which he did. But the Ass was as discontented as ever, for he had to work harder than before: so he begged Jupiter for relief a second time, and Jupiter very obligingly arranged that he should be sold to a Tanner. But when the Ass saw what his new master's trade was, he cried in despair, "Why wasn't I content to serve either of my former masters, hard as I had to work and badly as I was treated? for they would have buried me decently, but now I shall come in the end to the tanning-vat."
Servants don't know a good master till they have served a worse.
Aesop's Fables: A New Translation by V.S. Vernon Jones with illustrations by Arthur Rackham (1912). This book is available online at Project Gutenberg.