"ANCIENT WISDOM" INDEED;
EXTRAORDINARY PROCESS OF SWAPPING AGE FOR SENSUAL PLEASURE ;
King Yayati had two wives , Sharmishtha and Devayani. Sharmishtha was the daughter of Vrisha Parva, the king of the danavas (demons). And Devayani’s father was Shukracharya, the preceptor of the demons.

Devayani gave birth to Yadu and Turvasu and Sharmishtha gave birth to Druhya, Anu and Puru. 

Yayati ruled the world extremely well for many years. He performed many yajnas. But eventually he grew old. The problem was that although Yayati grew old, he was not yet tired of sensual pleasures. He still desired to savour the joys that the world had to offer. 

Yayati told his five sons. "Because of Shukracharya’s curse, an untimely old age has come upon me and I am not content with what I have savoured of life. I request one of you to give me his youth and accept my old age in return. When I have sated myself with worldly pleasures, I will take back my old age and return the youth." 

Except for Puru, the other four sons flatly refused such an exchange. They had no desire to part with their valued youth. They were thereupon cursed by their father. (Although not mentioned in the Matsya Purana., the curse was that they or their descendants would never be kings.) 

As for Puru, he said, "Please accept my youth and be happy. It is my duty to serve and I will gladly take upon me your old age." For a thousand years Yayati savoured the pleasures of the world with Puru’s youth. A thousand years were not than enough to satisfy Yayati. He accepted his old age and returned Puru’s youth. He blessed Puru for his obedience and announced to the word that Puru was his only true son. 

[Translation of original Sanskrit text from Matsya Purana].