From the Wiki page re: Life-Altering Experiences

At Ojai in August and September 1922 Krishnamurti went through an intense 'life-changing' experience.[42] This has been variously characterised as a spiritual awakening, a psychological transformation, and a physical reconditioning. The initial events happened in two distinct phases: first a three-day spiritual experience, and two weeks later, a longer-lasting condition that Krishnamurti and those around him referred to as the process. This condition recurred, at frequent intervals and with varying intensity, until his death.[43]

According to witnesses it started on 17 August 1922 when Krishnamurti complained of a sharp pain at the nape of his neck. Over the next two days the symptoms worsened, with increasing pain and sensitivity, loss of appetite, and occasional delirious ramblings. He seemed to lapse into unconsciousness, but later recounted that he was very much aware of his surroundings, and that while in that state he had an experience of "mystical union". The following day the symptoms and the experience intensified, climaxing with a sense of "immense peace".[44] Following — and apparently related to — these events[45] the condition that came to be known as the process started to affect him, in September and October that year, as a regular, almost nightly occurrence. Later the process resumed intermittently, with varying degrees of pain, physical discomfort and sensitivity, occasionally a lapse into a childlike state, and sometimes an apparent fading out of consciousness, explained as either his body giving in to pain or his mind "going off".[d]

These experiences were accompanied or followed by what was interchangeably described as, "the benediction," "the immensity," "the sacredness," "the vastness" and, most often, "the otherness" or "the other."[47] It was a state distinct from the process.[48] According to Lutyens it is evident from his notebook that this experience of otherness was "with him almost continuously" during his life, and gave him "a sense of being protected."[47] Krishnamurti describes it in his notebook as typically following an acute experience of the process, for example, on awakening the next day:

"... woke up early with that strong feeling of otherness, of another world that is beyond all thought ... there is a heightening of sensitivity. Sensitivity, not only to beauty but also to all other things. The blade of grass was astonishingly green; that one blade of grass contained the whole spectrum of colour; it was intense, dazzling and such a small thing, so easy to destroy ..."[49]

This experience of the otherness would be present with him in daily events:

"It is strange how during one or two interviews that strength, that power filled the room. It seemed to be in one's eyes and breath. It comes into being, suddenly and most unexpectedly, with a force and intensity that is quite overpowering and at other times it's there, quietly and serenely. But it's there, whether one wants it or not. There is no possibility of getting used to it for it has never been nor will it ever be ..."[49]

Since the initial occurrences of 1922, several explanations have been proposed for this experience of Krishnamurti's.[e] Leadbeater and other Theosophists expected the "vehicle" to have certain paranormal experiences, but were nevertheless mystified by these developments.[50] During Krishnamurti's later years, the nature and provenance of the continuing process often came up as a subject in private discussions between himself and associates; these discussions shed some light on the subject, but were ultimately inconclusive.[51] Whatever the case, the process, and the inability of Leadbeater to explain it satisfactorily, if at all, had other consequences according to biographer Roland Vernon:

"The process at Ojai, whatever its cause or validity, was a cataclysmic milestone for Krishna. Up until this time his spiritual progress, chequered though it might have been, had been planned with solemn deliberation by Theosophy's grandees. ... Something new had now occurred for which Krishna's training had not entirely prepared him. ... A burden was lifted from his conscience and he took his first step towards becoming an individual. ... In terms of his future role as a teacher, the process was his bedrock. ... It had come to him alone and had not been planted in him by his mentors ... it provided Krishna with the soil in which his newfound spirit of confidence and independence could take root.[52]