What is Nirvikalpa Samadhi?

The following is an excerpt from a samvaad (dialogue) session with Acharya Prashant.

Questioner (Q): Sir, my assumption about the Nirvikalpa Samādhi and Jāgrat Suṣupti that you talked of is that in that state, one enters into the ‘new’ each moment as one doesn’t allow the ego to make its grip on to anything. Is the fate or state of the one in that choiceless state different from the one not in that state after the death of the physical body? If not, then why is it so important to be in that state even if it’s one’s nature and ultimate desire? If yes, then who wants to know how? And if yes and the ego dissolves, I don’t see any reason why the ego might not emerge again because it did emerge without any cause or reason in the first place. The ego clearly doesn’t want to surrender so easily, it is revolting. I seek your help.

Acharya Prashant (AP): As it is revolting, it can only revolt only in its own bizarre and non-sensical fashion. On one hand, in the initial lines themselves, you say that the state of Nirvikalpa Samādhi or Jagrat Sushupti is one of choicelessness.

On the other hand, you are saying that in that state, one doesn’t allow the ego to hold on to anything, if that state is of choicelessness, where is the question of allowing or not allowing? Allowing certainly proceeds from a choice. You could have not allowed it. Who is there to…