The essence of a sentient being is unchanging; unchanging like the space in front of your face or in your room or your yard or in cosmos. The air in that space can be altered but not the space itself. Nothing can pollute it or adjust it. It is beyond time pure, has always been, and will always be so. Essence, primordial awareness is similar.
If one has trained in meditation and contemplation, the essence of Awareness-Being, (we’ve been calling it Presence) is present from the get-go of a session. If one clings to it, it is like water running through the fingers or like trying to grasp and hold onto space with one’s hand. If one is inattentive (distracted or preoccupied for example) one will not notice already present Presence Moment Awareness. But, if one softens and opens to the essence or heart of Awareness, there it is. And always was.