King Santanu, while he rejects the condition imposed by the fisherman is unable to forget the girl. One day in a typically round about way speaks to his son about how the Vamsha of the great Kurus run a risk as he is the only son. While he is not keen to marry, ... 'The wise have said that having an only son is like having no son at all'. The prince being perceptive as well proactive gets the story from his father's charioteer. Travels to meet the fisherman and tries to persuade him to drop the conditions. The man while seeming to agree, says he is helpless as a prediction, that a son of his daughter Satyavati would be monarch, is in the way. While he is aware that the prince is the crowned 'Yuvaraja', he does not budge.
Finally an agreement is reached as Devavarata yields and promises not to make a claim to the throne and further makes a vow to remain celibate, in response to the fisherman's fear that his children could lay a claim to the kingdom.
As the heavens, pleased with his supreme sacrifice, showered flowers on him and the word 'Bheeshma' resounded from the sky, Devavrata speeds towards Hastinapura with his new found 'Mother'.
(The story sounds very familiar!. Attraction to fisher women by town folks seems age old!
We see that while the Prince is intelligent he is also 'Abnormally' unselfish. He probably wanted to recompense his father as he and his mother Ganga just vanished on that fateful day.
(While Devavrata is soft on his father, his mother Ganga seems to be rather hard on the mortal she married! Obviously, Goddesses do have a different set of standards.)
It surprised me that a fisherman had the temerity to lay down conditions to a King, but I suppose the society was less complex and more equal those days. More impressive was his skill in negotiations! It is said that eating fish is good for the brain and this fisherman definitely proves it! See the way he takes advantage of a prediction made by a sage!)
(It is still possible if you consider how Anna Hazare a villager outmaneuvered the very clever and seasoned politicians!
Obviously we mortals have adapted and improved upon the heavenly practice of celebrating with flowers. Look at the way our netas are garlanded! Bigger the garland more the respect!