Translation: Sanjaya said: Thus have I heard the conversation of two great souls, Krishna and Arjuna. And so wonderful is that message that my hair is standing on end.
Explanation: The last time Sanjaya had spoken was in 11.50 where he expressed his astonishment at seeing the universal form of Krishna. Now, once again, he is experiencing an even greater ecstasy as manifested by the external symptoms of "hair standing on end." In the Nectar of Devotion, Srila Rupa Goswami explains this is one of the symptoms of extreme spiritual bliss. Sanjaya is experiencing the bliss of having heard the most exalted conversation betwen the Lord and His devotee. Srila Prabhupada comments, "The conversation was wonderful because such an important conversation between two great souls had never taken place before and would not take place again. It was wonderful because the Supreme Personality of Godhead was speaking about Himself and His energies to the living entity, Arjuna, a great devotee of the Lord. If we follow in the footsteps of Arjuna to understand Krishna, then our life will be happy and successful. Sanjaya realized this, and as he began to understand it, he related the conversation to Dhritarashtra."