It's a great book - personally I like how you can understand the message - and it is so clever - but it is very difficult to explain in words. It proves visual genius and esp in use of the camera.
Incidentally (very incidentally) his 'quirky thoughtfulness and pleasant sense of humour' seems to be mainly in his images. Like many of the best comedians he can be very dark and terse in person, with seemingly little patience for fools.
The Magnum Agency enabled him to nurture his particular approach to photography over a long time. He has another good quote "It is about time we started to take photography seriously and treat it as a hobby."