That book is life changing, if it's 'How To Win Friends'. Maybe for an older person, this stuff is trivial, but for a younger me, it taught me just how much we as a species think only of ourselves, how you can never win an argument, how you cannot browbeat someone into submission. You can at best hope to make the other person want to do something. Look at things from their perspective.

Stephen Covey seemed to hate Carnegie's book too, as if the book was written by a moustache-twirling supervillain. It's not. It's just a very lovely look into human psyche, beautifully illustrated by tonnes of examples (rather than the platitude-filled bullshit that is inside modern books by Ryan Holiday and company).