Sat-chit-ananda refers to:
Being-Consciousness-Bliss
Presence/Isness = Being
Awareness/Experience = Consciousness
Ananda = bliss.

The realization of our pristine blissful true nature is the realization that Presence/ISness and Awareness/Consciousness are One… That is the ‘I AM THAT’ reference.
The (non-dual) realization that the absolute and the manifest are one … reveals the eternal bliss of our True Nature.

The living understanding is that the substance of all phenomenal events is the substanceless Self. All forms are manifestations of the formless … arising out of the formless … made out of the formless … perceived by the formless… the one reality.

Once this understanding is revealed to be your living uninterrupted experience, you are effortlessly established in the Self, without wavering.

The non-dual realization is the realization of ISness as myself … as everything and everyone.