This has to have been one of the most influential books I ever read. Simple - elegant - nothing to remember - no jargon - no 'beliefs' to swallow - I read it in one go, and wandered around with what felt like an inner smile for days.
There's a website, with experiments, etc, here
However, I am well aware of what Douglas Harding says in his intro - after having his first experience of headlessness.
'Discussion proved almost invariably quite fruitless. "Naturally I can't see my head," my friends would say. "So what?" And foolishly I would begin to reply: "So everything! So you and the whole world are turned upside down and inside out..." It was no good. I was unable to describe my experience in a way that interested the hearers, or conveyed to them anything of its quality or significance. ... Here was something perfectly obvious, immensely significant, a revelation of pure and astonished delight - to me and nobody else! When people start seeing things others can't see, eyebrows are raised, doctors sent for. And here was I in much the same condition, except that mine was a case of NOT seeing things. Some loneliness and frustration were inevitable. This is how a real madman must feel (I thought) - cut off, unable to communicate.'
Look at this site translating Lao Tse through Douglas Harding's eye(s)