We know we exist.
You are there, in your reality, conscious and experiencing things, as I am in my reality, as self or identity.
And there is a whole, we usually do not think of, of whom our existence and more are parts.
As a part of our whole, we are a part of Reality.
Our whole may permeate us, and Reality may be immanent in us, but only in our being a part of our whole. We must present, open and surrender our self, in our being a part, to the presence of our whole being, who is of Reality.
“Everything that is of you and your reality, is a part of your whole.”
i What we experience (you and I, as self or identity), is difficult to determine. If we try to pin it down to what it definitely is and prove or question on what basis we know what something is, it‘s all words and what we experience. Like science, because science is a part of the mind, nothing is proven right or true, except in certain conditions or particular contexts eg. relativity for things in space and time, quantum for things smaller than atoms, Newton’s law of gravity for things in space and time at relatively slow speeds and short distances and time, relative to the speed of light.
ii We have different types of experiences (good/bad, past/ present, mind/feeling/body etc), various identities (varies with different company or situations), broader/narrower or faster/slower minds, deeper states of being, and different states of consciousness and stimulation (arousal).