The story of Nahusha, the son of Aayu and father of the Yayaati, clearly shows us what un-attainable high positions one can achieve as long as he has vinayam and what drastic downfall can happen if one has ahankaar.
Nahusha was raised in his childhood by the great Brahmarshi Vasishta. Since he was unaffected by happiness or sorrow and did not feel the slighest ahankaar when once Devatas praised him in his childhood, he was named Nahusha. He learnt all shaastras and after his education became the King. Due to his great qualities his fame spread quickly to all directions. Everyone was in praise of him, to such an extent that even vedas praised him. He performed 100 Ashwamedha Yaagas and hence was deserving the position of Indra.
Once, Indra killed an asura by name Vrutraasura. Though Vrutra was an asura, he was a braahmana and hence Indra had to suffer
brahmahatyaa-paatakam and Nahusha was offered the position of Indra. Nahusha continued to be good, until one day he realized that he was the ruler, king of all the 14-lookas! He suddenly became very proud and once a person has Ahankaar, he does not think, he assumes he is the greatest and that he can never be wrong. Such was the power of being the king for the Devatas and all the worlds! He sends a message to Sachi-devi, the great Pativrata and wife of Indra (the previous Indra, the eldest brother of Devatas) that she must serve him as he is the Indra now. The very moment he wanted a Pativrata, all his good qualities, tapas-shakti everything were lost and his end was destined.
Sachi-devi tells Nahusha "O great Indra! You are the God of the Gods. You are very great, please come to my house. But you being so great deserve to be carried by none other than Saptarishis. So please come in a pallaqi beared by them". Nahusha really feels that what Sachi-devi said is true (did not realize that she was a pativrata and hence the real meaning behind her words) and immediately ordered the Saptarishis to do so. Obviously the Saptarishis have conquered anger and ahankaar so they carry him. Nahusha sits in the pallaqi beared by them and in the height of his pride says "Sarpa Sarpa" (go fast) to Agasthya muni, since he was very short and was taking small small steps. Agasthya muni said "sarpobhava", in order to teach Nahusha a lesson. And immediately from the high position of Indra, he falls as a Ajagaram (huge Python) in some deep forest.
He spends thousand and thousands of years repenting for his mistake. Once when Paandavas were in the aashramam of Vrushaparva, Bhima goes to the forest and sees Nahusha who was in the form of an incredably huge Ajagaram. Bhima gets surprised by the amazing strength of it and asks it who it was. Nahusha tells his unfortunate story and says only the great Yudhishtira, who never deviates from the path of truth, can save him from this form. Meanwhile, Yudhishtira searching for Bhima reaches that place. Yudhishtira on knowing that the ajagaram is his ancestor Nahusha, he prostrates to him and takes his blessings. Later he answers all the questions of Nahusha and Nahusha gets freed from the terrible form, takes the form of a divya-purusha and goes to urdhva lokas in a divya vimaana.
Morals in the story:
As long as Nahusha had Vinayam he was respected by everybody. Once taken over by Ahankaar, he committed great mistakes and later had to experience the result.
Even for a great person like Nahusha, the power of simhaasanam made him bad. One must be more and more careful to be good and humble as his power in the society grows.
Yudhishtira showed the way elders must be respected. One must never evaluate an elder for respecting them. According to our culture they always must be respected.
Gnyaanam, knowledge of shaastra helped Yudhishtira answer the questions of Nahusha. One must always give utmost importance to gnyaanam and vigyaanam — using them one can acheive great wonders and help others.
Pativratas power is graeater than anyone. One must never want a para-kaanta.