I like the “Smile” by Dale Carnegie, but not all of the time because you come across as weird.

The waiters remember us across the years as a couple in Cancun, Mexico. We actually smile at each other during dinner. That’s sad.

For me, one thing that made a difference was this question: “What are Your Values — Write them down.”

These books push you to think instead of pass blindly through life.
Good article.