The Man in the High Castle is definitely a book that stays with you. Dick even said that he refused to revisit it because it took such a toll on him to write it. (That said, it has an amazing tv adaptation that differs enough that both stand on their own as related, but separate entities)

I really liked the sci-fi writer Adam Roberts's description of Philip K. Dick's writing -

"A sense of something hidden, something underground and flourishing in the interstices, like bluebells growing in the cracks of the pavement (or blooms of mors ontologica in amongst the corn) energises his fiction. It's this something that has kept his books alive when better written, better structured and better plotted novels have fallen into obscurity around them. Which is to say that critics can, and do, point to evidence of hasty writing in Dick's works, patches of ragged or inexpressive prose, or occasional addled-head-ness in most of his books (he took a whole bunch of drugs, after all). But even with all that, or conceivably because of that there is a quality that PKD's books possess that few other books, in or out of genre, can match. It is a sort of fascinating aesthetic uncleanness, resonant and enduring. More polish would have rubbed that quality away."

Taken from this review if anyone wants to check it out.

I read Man in the High Castle, maybe 30 years ago. I was perhaps 15? Likely, too young to fully understand and appreciate the literary value and the story (and story within a story). Read it in the last few months, as a person with a little more life and found an entirely new admiration for it. Though, I’ll admit, if not for the Amazon series of the same name, I likely would have missed out on picking it up again.

Hello. I read an interesting fact about this book, and to be precise, about the process of writing it. You know, there is such a thing - I Ching, or Book of Changes. So, so with the help of a coin toss, you can supposedly determine the probability of an event, this is something like a prophet or an oracle. This is also mentioned in the book.

And so... the author wrote "The Man in the High Castle" using this book of changes. Should heroes go one way or another? Should the heroes of the book meet or not? Should the hero of the book fall in love with a woman or not? And everything in that spirit was decided by a blind chance, a coin toss.

When I found out this, it opened my eyes to some plot twists, partly explained the ending of the book, and in general it became clear why the plot behaves like a yacht in a storm.

I do not pretend that this is not really the case, but what the author loved... let's just say experimenting with various mind-expanding substances... it might have been just like him.

I wonder if being familiar with I Ching might change my appreciation of the book. I know what it is, and assuming his depiction is accurate I learned something more, but maybe a better background would give more insight into what the characters were doing.

Like Tarot, the I Ching has a lot to offer, and little of it has to do with telling the future. It's more about looking into the unconscious/subconscious. Just thought I would add that in case you decide to go down that route.
I would highly recommend the Tao Te Ching and I Ching to anyone.

I understand. But just imagine that, for example, Shakespeare is like, "Hmm... Will Romeo fall in love with Juliet? Well, I'll leave everything to chance!" A little strange, as for me.

What you’re doing here is refusing to suspend your disbelief.