There's nothing really new in that book now - the ideas seem to have become part of the mainstream, or at least common knowledge to the mainstream. Not surprising, since the ideas are 46 years old. Though it no longer has that 'wow' factor, it's still worth a read - it likens taking care of our bodies and minds to that of taking care of the external and internal workings of a motorcycle, and shows that you can't focus on only one aspect if you wish it to function well for a long time.
The following quotes spoke to me. The first, for reminding us to look closer, open our minds, and to acknowledge blockages, and the second, for reminding us of the value of regular practice to get better at something (I had writing in mind):
"If you're plagued with value rigidity you can fail to see the real answer even when its staring you right in the face because you can't see the new answer's importance." (p 311)
"If you're a sloppy thinker the six days of the week that you aren't working on your machine, what ... can make you all of a sudden sharp on the seventh?" (p 325). Practice, practice, practice. And then practice some more!