Thanks for your response.
Regarding Arabia, I agree that it is not known in modern times what is meant by the term. I’m working on the assumption that Kamal Salibi got it right in his book The Bible Came from Arabia [I’ve discussed that and his work at length in this article]. He suggests the area which is today Asir and the southern part of the Hijaz, just north of Yemen. This makes sense, given everything he says, especially in relation to Christianity, and to Paul.
You’re also right about the mushrooms; they weren’t absolutely necessary. The same or similar experiences can be had by other means. [By coincidence, that will part of the topic of my next article in the series.] However, entheogens would be a likely explanation for someone who was new to a religion, like Paul. He says that he spent three years in Arabia. That would probably be enough time to go through the necessary spiritual practice, asceticism, in order induce such an experience. But it’s possible, and feels right to me, that he had this experience fairly early in his stay there.[He would have needed time afterwards to reflect, and formulate his theology before returning.] In any case, it seems obvious that he had been initiated into a Mystery tradition, and it is well known that they used psychoactive substances as part of their initiations, so I think some such substance remains the most likely explanation.