The Last Relinquishment:
When ignorance of the 4 Noble Truths finally
fully evaporates,
One no longer clings to any sense pleasure, any views, or any rules and
rituals!
One no longer clings to any idea of a self, I, Me, Ego, Soul or Identity at
all...
When one does not cling, one is not agitated! One remains imperturbable...
When one is not
perturbable, one attains the state of Nibbāna right there!
One then understands: Rebirth is ended, this Noble life has been completed,
What had to be done is done, there is no more relapsing into any state of
being...

Nibbāna is a
Phase Transition of Consciousness!
More on
Nibbāna
A quenched state of Peace, Freedom, and supreme Bliss:
The_2_Nibbanas,
The_Uncreated,
How_to_Enter,
Doctrine of Nibbana,
The_Signless_Nibbana,
Nibbana_Still,
Imperturbable_Equanimity,
Climax of
Calm, Final Freedom,
The
Proximate Cause,
Peace,
What_is_Nibbana,
Nibbana or non-return,
Reaching
Peace,
Nibbana_True_Peace,
The_Entrance,
The_Unborn_State.
Source:
Majjhima Nikāya I 68: The shorter speech on the Lion's Roar.
Ignorance Meltdown!