> It is the meta-ability to observe its own perceptions and thoughts. And a sense of self, a sense that the observer is the same over time.
Which is kind of strange because folks who achieve insight examining their own perceptions and thoughts seem to dissolve the barrier between self and not-self.
But even then most such reports still effectively claim a subjective experience.
Not always, ego death states are not needed.
Meta-cognition is a common skill a lot of highly intelligent people possess but of course if you don't have it you can still be highly intelligent, just not as aware.