Many unnecessary digressions

I was disappointed by this book. Some tips are very useful, but they are all contained in the last chapter ("the party of Ten"). The rest of the book is finally often a waste of time for anyone who seeks to know the ABC of good manners. Many unnecessary digressions on topics such as job interviews, historical anecdotes ... In short, it is a shame because some subjects could have been better developed (the various rules of politeness in different countries of the world, eg ).