When engaging in meditative or spiritual practice, one will encounter many different types of experiences along the path. Some of these can be mildly pleasant, some very pleasant, and some can be extremely unpleasant.
If one can assumes that their practice will only lead to ever-deepening positive and pleasant states of mind and body, when the reality kicks in, they may be in for an unpleasant surprise. This is why I think it is crucial to be better informed about what meditation can lead to.
The Visuddhimagga (Pali for The Path of Purification) is the 'great treatise' on Theravada Buddhist doctrine written by Buddhaghosa approximately in the 5th Century in Sri Lanka. It does a very good job at elucidating the meditative journey.
Here are some of the experiences, based upon the Visudhimagga, my own experiences on long-retreats, as well as the experiences of my fellow meditators and teachers (For a comprehensive treatment of the states and stages, please look up The Progess of Insight):
- Mind and Body - This is a pleasant stage which arises relatively early when one begins to concentrate and investigate the mind. One begins to see that experiences can be divided into two types: Mental and Physical phenomena. Before this insight stage, a person can be completely embedded and identified in their experience. At this point, one can observe experiences with a certain detachment.
- Cause and Effect - This is a semi-pleasant stage in which the meditator starts to notice the arising of intentions. Before this stage, one is completely embedded in intentions. At this point, one can notice the arising of an intention that precedes actions.
- Three Characteristics - This is an unpleasant stage in which the meditator begins to notice the three characteristics of all mental and physical phenomena: They are all coming and going (Impermenance), none of them can truly satisfy (Suffering), and they are not caused by anyone nor do they belong to anyone (Not-self).
- Rapid Arising and Passing Away - This can be an extremely pleasant stage which is also sometimes called Pseudo-Nirvana) because it tricks many people into thinking this is Enlightenment or Awakening. It is actually far from it, and characterised by a certain hubris, and attachment. It can also involve intense joy, rapture, seeing lights, and all sorts of other impressive phenomena.
- Dissolution and Knowledge of Suffering - These are a series of stages where the meditator begins to have deeper insight and understanding of the difficult aspects of being alive in any form. These states can involve different layers and levels of difficulty and anguish. They are also commonly known as "The Dark Night of The Soul", and can be quite a contrast to the beautiful spiritual highs that preceded them.
- Equanimity, High Equanimity, and Nirvana - If a meditator continues to practice through the difficult stages, they may discover the mind which stops reacting to anything. The mind can come to a place of stillness, a perfect equilibrium.
If the meditator doesn't stop there, Equanimity can become so strong that one can spend hours without moving, staring into vast Emptiness. Non-experiences (Nirvana) can also begin to manifest at this stage, with the attainment of Stream Entry, the first stage of awakening according to Theravada Buddhism.
It is best to always work with a highly experienced and qualified teacher rather than trying to self-analyse one's practice, as it is very easy to delude oneself.
May your practice unfold well!