It has happened: at age 68, after many years of spiritual research, discipline and practice, I attained to Arahant. I want to acknowledge Daniel's insights and experiences, since mine were and are very similar, tending to validate his model.

Before discovering the Buddha's teaching I was a student of Bhakti and Vedānta. I was a Hindu monk and disciple of a prominent Indian guru for over 30 years. I practiced and attained everything that was described in that path (BTW I do not subscribe to the usual interpretation of Vedānta attributed to Śāṅkarācārya) and even became a guru myself. But I felt incomplete and unsatisfied, leading to resigning my position and beginning my search anew. 

I determined to base my new search for truth on experience rather than faith. This led to research into Existentialism, especially Heidegger. After seeing some of my videos online, a friend told me, "Your understanding is very similar to Theravāda Buddhism." I had encountered Buddhism before, of course, but during my early search in the 60s Theravāda was not readily available in the West. I didn't like Tibetan Buddhism because it seemed a recast of Hinduism, and Zen seemed to have a lot of background missing.

But as soon as I read some books by Buddhadasa Bhikkhu, I could see that Theravāda was a lot closer to the original teaching of the Buddha. So I got some copies of the Suttas and dove in. I went to Thailand but could not find a monastery where I felt comfortable. Buddhadasa's disciples had largely given up his radical Suttānta stance and caved in to government pressure to conform to the orthodoxy. I got an invitation to go to Sri Lanka and went there to study. I was ordained as a monk and lived in a forest monastery for almost two years.

Here I should backtrack and recount an episode from the 1980s. After my Indian guru passed away I became interested in Rajneesh ('Osho') and investigated, even visiting his commune in Oregon. I could not stand his organization, which seemed infected by sociopaths. But I was impressed by the breadth of his work, even if it seemed rather shallow at times. Anyway I started to study his methods and after some time, settled on his book Secret of Secrets, a presentation of the Chinese classic The Secret of the Golden Flower (T'ai I Chin Hua Tsung Chih). I had some background in Chinese martial arts and Taoist energy work, and it made sense to me.

I took about two months out from my usual practices to study this method intensively. I started sitting meditation and worked up from 2 hours a day until I was doing virtually nothing else every waking moment. I could only sit for 20-30 minutes at a time, then would take a break and stretch, sit right back down and start again. After about six weeks of this practice, I had what I can only describe as an oceanic experience of universal bliss. All the usual symptoms of Kuṇdalīni manifested, along with a vision of all-pervading consciousness and light. I was high for weeks afterward. At the time I interpreted this as realization of Brahman, but later on as I understood the Buddha's teaching I could understand that this was Stream Entry. I read of many similar experiences on this forum.

Fast-forward to two years ago. Living in the forest monastery, in a kuṭi with a spectacular view overlooking the whole southern province of Sri Lanka, I had two more breakthroughs, much subtler and deeper than I had experienced in 1984. I'm not going to describe all the details here because it would make this much too long. In each case, I was not pursuing any specific kind of enlightenment or realization, but simply plugging along with my study and practice of the Suttas. The experiences were spontaneous and unexpected, which helped to convince me they were genuine.

I should mention that for a long time I had doubts about my 1984 experience, until my studies convinced me that it was Stream Entry. As soon as I acknowledged the attainment, I felt much better about everything. Doubting attainments leads to confusion. Part of the mind, the intuitive wisdom, knows very well what you have attained. Another part, the social superego, is afraid of what other people will think. Over time I have learned to trust my intuition.

As you may well imagine, my realizations led to a deep conflict with the orthodox Buddhist monks and society. Many of these issues have been well-discussed on this forum and do not require elaboration here. I left the monastery and began to live independently as a monk. During this time I continued writing and making videos, gradually taking responsibility for my attainments. And of course, I kept up my practice. I should mention that during this time I got an introduction to Bhikkhu Kaṭakuruṇde Ñāṇananda. I was able to visit him and get his blessings. More than anything else, his teachings opened up the mystery of Nibbāna for me.

I was invited to Norway last summer to teach at a spiritual center. It was not an especially happy time. The Norwegians are, socially and consciousness-wise, where the US was in the 1950s: enjoying lots of material abundance, naively thinking it will bring happiness. So teaching Theravāda there was like trying to teach the calculus to kindergartners. People were looking for a pleasant 'spiritual' vacation with some nice entertaining stories. They did not want to be challenged to think or pursue deep insight. So it was rather unsatisfying but I got a lot of good coursework and practice done. 

It happened on the plane, on the way back to Sri Lanka. I was sitting next to a nice educated Arabic couple with an infant. As usual I was meditating and of course the baby was fussy. So I had to concentrate especially hard to keep focus. On the approach to Dubai I reached a peak of concentration. Suddenly I clearly saw the cause of suffering and its cessation. I experienced this:
The Sutta phrase "Released. There is nothing more for this world," spontaneously arose in my mind. Unfortunately I could not just relax and savor the moment, because shortly we landed and I had to endure the usual airport nonsense. But once I landed in Sri Lanka and got back to my kuṭi, I was amazed how my internal state had changed. Huge chunks of mental stuff were just gone, everything was very clear within, and I could not doubt that something very profound had happened. I spent three weeks hardly eating or sleeping, just absorbed in the attainment, trying to understand the significance of it all.

Of course, this was the final nail in the coffin of my relationship with Buddhist orthodoxy. Although I haven't posted anything specifically about being an Arahant, I have caught quite a bit of flak on orthodox Buddhist forums for views expressed in my videos and writings. Oh well, I don't consider those people's association especially beneficial, anyway. But it's too bad that 'Buddhists' have now become just like the Brahmins in the Buddha's time.