What is the secret power of Tolkien's Lord of the Rings?

There is, there must be, more to Tolkien's Lord of the Rings (LotR) than meets the eye - or has been explained by even the very best literary critics; some-thing that goes beyond what a simple work of fiction can achieve. 

This is evident in the initial impact of LotR when I read it aged 14; and was confirmed by the unique intensity and duration of my lifelong engagement with the book. 

I remain fascinated and gripped by LotR; even after uncounted re-readings, background scholarship on the early drafting, adaptations, artwork and a great deal of 'secondary literature' of comment, criticism and analysis. And mainly such a lot of thinking and imagining!

For me, there is nothing else even remotely like this in my life. I am by nature a re-reader, and a background reader; so I have re-read many books many times, and read many biographies of many authors and so on. I have also had recurrent thoughts and imaginings from other books. Yet none of them come anywhere near to the effect of Lord of the Rings. 

Whatever the reason for this may be, I think it hit home immediately; on the first reading. So that probably holds the clue. 

My memory is that I believed LotR was true, and more-true than the normal work around me. This was evident to some of my friends, including the one who introduced me to the book who I heard say this with a mixture of frustration and mockery. To him I was taking it all much too seriously.  

Most people would agree - but from where I am, more than forty years later, I was dead right. Tolkien is realer than ordinary real life - and this has become more true with every passing year as 'real life' became more fake, 'virtual', evil and is now almost-wholly dishonest and deluded. 

But I still find it hard to say just why this is the case, or why this fact was so evident to me so quickly.