Comments and expansion
Sam Harris
And you think "well, there it is, meditation is finally working". Notice that inclination to grasp at a transitory experience.
Here, Sam Harris talks about meditative states, and the error of confusing mere experience with true insight.
Experience and realized essence in Mahamudra
In general, classical Mahamudra authors warn about confusing experience with realisation (insight).
In the following quote, the author also warns of the dubious effect of mere experiences on the person's character: they tend to blow up the ego and they lead to boasting .
In brief, the borderline between an ephemeral experience and the realized essence is that when there is an experience—no matter how stably bliss and clarity may occur in the mind—its essence is not realized and its nature is not known. Experiences are stained by such conceptual mental stances as doubt, fixation on attributes, and clinging to superiority, as well as pride, self-importance, and verbally spouting one’s conviction. (Khamtrul & Abboud, 2020, p. 225)
Tashi Namgyal: Bliss, clarity and nonconceptual stillness
Daniel P Brown often refers to Tashi Namgyal. Namgyal identifies three main categories of experience that can deceive the meditator: bliss, clarity, and nonconceptual stillness.
These experiences are closely related with intensive concentration meditation (shamata):
A very strong samādhi is likely to have the three characteristics of bliss, clarity, and nonconceptual stillness, but that if it lacks insight practice, then it is impossible to realize emptiness, and therefore the practitioner fails to establish the foundation for enlightenment. (Brown & Thurman, 2006, p. 445)
But then, I remember from my trance state in the Level 1 retreat the repeated pointing out instructions:
Bliss: empty!
Clarity: empty!
No conceptual stillness: empty!
Bliss, clarity and non-conceptual still are not "bad" per se. They are regular and to be expected results of concentration meditation. They are motivating once they occur.
Only at a later stage of meditation (the meditation of non-meditation), bliss, clarity and nonconceptual stillness turn into meditative faults, if they are not recognised as mere experiences and therefore as "empty". They too are mere constructs and fabrications, to be discarded.
So, it´s not the experience itself, but the attachment to it that is the meditative fault.
Experiences through Psychedelics
That phenomenon is indeed also known as a potential undesirable result of psychedelic experiences.
The deceased Culadasa is greatly amused, for example, when he is confrontated in a Patreon Q&A with the statement "My ego became so small that I was god". Worth listening to. Btw my name comes up, so I don't have to spout : Culadasa does it for me.
Resources
Barth, P. (2007). A Meditation Guide for Mahamudra [PDF]. Mahamudra Meditation Center, Petaluma, USA. (Original work published 1998). Note: This book is not for sale in the trade.
Brown, D.P., & Thurman, R. (2006). Pointing Out the Great Way: The Stages of Meditation in the Mahamudra Tradition (Annotated). Wisdom Publications.
Culadasa (John Yates) [Patreon recordings]. (2021, September 17). Culadasa June 2020 Patreon Q&A N°2 Recording [Video]. YouTube. Retrieved 4 October 2022, from https://www.youtube.com/watch?v=a8XJrNx7iN0
Khamtrul, Rinpoche, & Abboud, G. (2020). The Royal Seal of Mahamudra, Volume Two: A Guidebook for the Realization of Coemergence. Snow Lion.
Namgyal, T. D., & Callahan, E. (2019, March 12). Moonbeams of Mahamudra (Tsadra) (Translation). Snow Lion. https://www.amazon.de/Moonbeams-Mahamudra-Tsadra-Dakpo-Namgyal/dp/1559394803