There’s a Buddhist thing I read years ago that gets you there.
It was a parable, old monk tells young monk thing, young monk does it.
Monk sits by river. noticing the river
After hours, noticing himself and the river.
Overnight, noticing the river after he’s no longer there.
Something like that.
I don’t know much about Pierce fist hand but that sounds like it.
It’s something like: We don’t usually notice we exist, or if we do we see ourselves as distinct-from.
But with practice, you can notice that you’re a part of the flow of things and can enjoy that experience. Folks go on Roller Coasters for a quick boost of that. I think all humans need it.
But you can take it a step further, once you are aware of your presence in an ongoing real-time way.
You can then subtract yourself from the flow of things.
I suppose that’s like being ok with being invisible at a party but a bit deeper.