Hi Mark,
I have never read the book, I hear that some parts of it are different from the film, is that true?
Now, that you remind me of Ken Kesey and his 60s magic bus, I realise it is pretty obvious that he was interested in the trickster myth and role in life. After all he was with a band of pranksters (tricksters)!
I am not sure how much you know about tricksters, so if I'm just telling you what you already know I apologise!
The trickster is a common character in many myths worldwide. The trickster can take many forms but is often the mischief-maker, the one who shakes up the existing state of affairs. This is often so that something new may emerge. In North American myth, the trickster character commonly takes the form of Raven or coyote. In World Mythology (Willis) it says:
Along the Pacific coast of North America the Raven is presented as discoverer of fire. He is also the trickster who outwits the enemies of humankind, a role played in other parts of the continent by the coyote, the hare and the spider, and among the Plains peoples by a figure called The Old Man or Old Man Coyote. These cosmic jokers have the important task of staking a claim for the freedom of the human spirit. They work for the right of humanity to assume the godlike role of re-making the world, even if the attempt on behalf of humanity involves a tendency toward ludicrous and sometimes disastrous mistakes.
If you look at the film "One flew over the Cuckoo's nest", it appears that McMurphy takes on the role of trickster. He comes to the hospital and really shakes things up, he is strongly opposed to the laws put down by Nurse Ratched. He's mischievous, creates uproar, creates entertainment...but with disastrous consequences for himself.
Chief, on the other hand, has been seemingly inspired by this example...it's as if he's learnt his lesson from this trickster and finally has the strength he needs to break free.
I read some reviews of the other book you recommend, "Sometimes a great notion", many seemed to like it even more than "One flew over a cuckoo's nest" - thanks for the recommendation, I will try and read it one day!