I absolutely loved 'The Secret' when I read that book 10 years ago. It completely blew my mind and I was so inspired by it. Things did start positively changing for me too, as soon as I'd finished it and I went on to read and investigate other books on the Law of Attraction.
BUT, 'The Greatest Secret' has been a huge disappointment for me. As many other reviewers have rightly said, it just feels like a book of quotes and constantly repeats many points. There are summary sections at the end of each chapter and I kind of feel like the book could have just contained those parts only as they got to the point, without too much 'padding'.
If this was someone's first experience of The Secret and/or reading about a higher power and consciousness, I think they'd be left totally confused and thinking it was a load of 'fluffy' rubbish. I don't feel the book did any justice to these concepts. I actually felt myself blushing at some points reading it as nothing was really 'explained' and I felt silly even taking some of it in (which was a challenge in itself to be honest).