A Man gave animals shelter and in return they gave him their attributes for various ages of his life: headstrong in youth, laborer later, then snappish.
The Ages of Man
A horse, Ox, and Dog, driven to great straits by the cold, sought shelter and protection from Man. He received them kindly, lighted a fire, and warmed them. He let the Horse make free with his oats, gave the Ox an abundance of hay, and fed the Dog with meat from his own table. Grateful for these favors, the animals determined to repay him to the best of their ability. For this purpose, they divided the term of his life between them, and each endowed one portion of it with the qualities which chiefly characterized himself. The Horse chose his earliest years and gave them his own attributes: hence every man is in his youth impetuous, headstrong, and obstinate in maintaining his own opinion. The Ox took under his patronage the next term of life, and therefore man in his middle age is fond of work, devoted to labor, and resolute to amass wealth and to husband his resources. The end of life was reserved for the Dog, wherefore the old man is often snappish, irritable, hard to please, and selfish, tolerant only of his own household, but averse to strangers and to all who do not administer to his comfort or to his necessities.
Canis, Bos, Equus, et Homo
Equus, bos et canis, frigore pressi, in hominis cuiusdam aedes convenere, qui, eos excipiens, accenso foco fovit ac deinde equo hordeum, bovi paleas obtulit; cani vero ex iis quae in mensa aderant dedit. Quam ob hospitalitatem ipsi gratias reddidere, singuli vitae suae tempus partiti eique gratificati. Equus itaque primos annos largitus est; ideo praecipiti mente et superba unusquisque hominum prima aetate est. Medios vero post hunc annos taurus dedit; ideo tunc laboriosus et sedulus est quisque studetque divitias cumulare. Ultimos tandem annos canis praebuit, et propterea senex quilibet morosus est, sibi victum dantem tantummodo amat, blanditur, assentiturque, non dantibus vero allatrat et insultat.