Pūrṇatvam, fullness. Because the truth of myself, sat (existence) cit (consciousness) ānanda (bliss) is the only thing that is, it is described as full. Because as this fullness I am the only thing that is, I only experience myself.

Vedānta exists to explain exactly how this works, and how person and his ground, consciousness relate to each other. Once I know, once I have my vision of existence complete, there is no outside, no inside, no other. Then I am the happiness of
fullness and infinity itself. Then I don't have to desire anything to be happy, then I don't have to be afraid of anything. Nothing can touch me as full consciousness, as the whole of existence.

This is the way to relax the apparent person (which I am free of). There is no more suffering or dissatisfaction. There is then the experience of total fulfillment of being independent on one's own. This is the nature of the self, ātman.

oṃ pūrṇamādah pūrṇamidam pūrṇātpūrṇamudacyate
pūrṇaśya pūrṇamādāya pūrṇamevāvaśiṣyate ||
oṃ śāntih śāntih śāntih ||

That's full and that's full. The full has come from the full.
The full of the full, only the full remains.
Aum peace, peace, peace.