The self comes about due to the attachment of memory with perception. Without memory there is no ego to be inflicted upon. An ego remembers everything. What attacked it what hurt it, what made it feel good. It is a self serving fool drunk on memory. No memory/no ego/no self. Down this path plants then can be considered to have a sense of self. Plants have the well documented ability to perceive their surroundings, phototropism and hydrotropism are two types of perceptive behaviour. Plants also display cellular memory. The plant Mimosa pudica is one example of a plant species that alters its reactions in response to differing external stimuli. This species of plants appears to know or learn what physiological response is best appropriate for a particular external stimulus (a drop, knock, or shock to their leaves for example).

TRANSCENDATALISM

“Also called Transcendent Experiences, Ego-Transcendence, Intense Religious Experience, Peak Experiences, Mystical Experiences, Cosmic Consciousness Sources Wuthnow, Robert (1978). Peak Experiences: Some Empirical Tests. Journal of Humanistic Psychology, 18 (3), 59-75.

Noble, Kathleen D. (1987). ``Psychological Health and the Experience of Transcendence.'' The Counseling Psychologist, 15 (4), 601-614.

Lukoff, David & Francis G. Lu (1988). ``Transpersonal psychology research review: Topic: Mystical experiences.'' Journal of Transpersonal Psychology, 20 (2), 161-184.

Furthermore, Greeley found no evidence to support the orthodox belief that frequent mystic experiences or psychic experiences stem from deprivation or psychopathology. His ''mystics'' were generally better educated, more successful economically, and less racist, and they were rated substantially happier on measures of psychological well-being.
(Charles T. Tart, Psi: Scientific Studies of the Psychic Realm, p. 19.)

Long-Term Effects
Wuthnow:

• Say their lives are more meaningful, think about meaning and purpose

• Know what purpose of life is

• Meditate more

• Score higher on self-rated personal talents and capabilities

• Less likely to value material possessions, high pay, job security, fame, and having lots of friends

• Greater value on work for social change, solving social problems, helping needy

• Reflective, inner-directed, self-aware, self-confident life style

Noble:

• Experience more productive of psychological health than illness

• Less authoritarian and dogmatic

• More assertive, imaginative, self-sufficient, intelligent, relaxed

• High ego strength, relationships, symbolization, values, integration, allocentrism, psychological maturity, self-acceptance, self-worth, autonomy, authenticity, need for solitude, increased love and compassion

Short-Term Effects (usually people who did not previously know of these experiences)

• Experience temporarily disorienting, alarming, disruptive

• Likely changes in self and the world, space and time, emotional attitudes, cognitive styles, personalities, doubt sanity and reluctance to communicate, feel ordinary language is inadequate

• Some individuals report psychic capacities and visionary experience destabilizing relationships with family and friends

• Withdrawal, isolation, confusion, insecurity, self-doubt, depression, anxiety, panic, restlessness, grandiose religious delusions

Links to Maslow's Needs, Mental Health, and Peak Experiences
When introducing entheogens to people, I find it's helpful to link them to other ideas people are familiar with. Here are three useful quotations.

1) Maslow - Beyond Self Actualization is Self Transcendence
"I should say that I consider Humanistic, Third Force Psychology to be transitional, a preparation for a still `higher' Fourth Psychology, transhuman, centered in the cosmos rather than in human needs and interest, going beyond humanness, identity, selfactualization and the like.''

Abraham Maslow (1968). Toward a Psychology of Being, Second edition, -- pages iii-iv.

2) States of consciousness and mystical experiences
The ego has problems:
the ego is a problem.

"Within the Western model we recognize and define psychosis as a suboptimal state of consciousness that views reality in a distorted way and does not recognize that distortion. It is therefore important to note that from the mystical perspective our usual state fits all the criteria of psychosis, being suboptimal, having a distorted view of reality, yet not recognizing that distortion. Indeed from the ultimate mystical perspective, psychosis can be defined as being trapped in, or attached to, any one state of consciousness, each of which by itself is necessarily limited and only relatively real.'' -- page 665

Roger Walsh (1980). The consciousness disciplines and the behavioral sciences: Questions of comparison and assessment. American Journal of Psychiatry, 137(6), 663-673.

3) Therapeutic effects of peak experiences
"It is assumed that if, as is often said, one traumatic event can shape a life, one therapeutic event can reshape it. Psychedelic therapy has an analogue in Abraham Maslow's idea of the peak experience. The drug taker feels somehow allied to or merged with a higher power; he becomes convinced the self is part of a much larger pattern, and the sense of cleansing, release, and joy makes old woes seem trivial.'' -- page 132

Lester Grinspoon and James Bakalar (1983). ``Psychedelic Drugs in Psychiatry'' in Psychedelic Drugs Reconsidered, New York: Basic Books.”

- https://csp.org/docs/states-of-unitive-consciousness