I shouldn't still be surprised at how evergreen the works of authors like Hill, Carnegie, and Schwartz are. Mindset and communication skills are always valuable, relevant, and something we could use a refresher on every so often.
I was amazed at just how many anecdotal and published stories Carnegie includes in here. His ability to gather and organize so much info on the subject of worry in the 1940's is hard to fathom. There's a huge variety of stories and personal self-improvement methods, from minor struggles to Depression-Era trauma. Along with many methods to curb worry, other topics were mentality, mind-body connection, criticism, forgiveness, failure, happiness, and philanthropy.