Like the title, the book is a little bit forward for my liking (could just be that the author is American), but nevertheless contains valuable insights. I was surprised to see that Carnegie takes a rather pessimistic view of human nature – I was fully expecting a 'shiny happy people’ sort of thing. His core thesis is that humans are highly self-centred and all of their behaviour towards you will be determined by how important you can make them feel. In effect, he provides a playbook for thriving in an imperfect world where people only care about themselves, or at least only care about you to the extent that they can further their own aims.
Much of the book is anecdotal in nature; though I took issue with this at first, I suppose that in the limit, anecdote becomes empirical fact (and he really does have mountains of anecdotes). It is readable and entertaining, and I think even sociable people might have something to learn from it.
EDIT (Dec 2021): I like to think I've become much more sociable in the several years since I wrote this review – university probably had some role in that! In hindsight, this book definitely changed the way I approach social situations, hopefully for the better. The words of Emerson have potently stuck with me:
In my walks, every man I meet is my superior in some way, and in that I learn from him.