No one has ever left the normal state of reality. Only perception. Certainly humans have been hallucinating and imagining things forever. Also, lying about your knowledge is a pretty universal human trait. Graham Hancock is proof of that.
No. But it didn't unfold itself to anyone else either. Shamans have never produced a single falsifiable hypothesis. Reality is exposed but by bit through observation and experimentation. Preferably while sober.
The combination of plants that creates ayahuasca appeared in a dream. Shamans have identified cancers and illnesses in people. If science can’t cope with these realities, that’s a science problem.
That's it. Shamans appear in disparate cultures over millenia upon millenia, helping people in astounding and near-inexplicable ways... And modern academia is just like, 'well, they believe in spirits and take drugs so they must be dumb - now off I go to work to pay my $400,000 mortgage, because that's sensible'.
We owe these traditions an astonishing unacknowledged debt, and the people telling us so are ferociously attacked.