In 1989 at age 19, I found Please Understand Me and Type Talk in the psychology section of a B Dalton bookstore, a popular chain that no longer exists. I had recently moved out on my own, serving popcorn at a movie theater to pay rent. At that age, poor communication skills and an inadequate understanding of people kept me isolated.
Growing up introverted with the same group of D&D friends through middle school and high school doesn’t push you to learn better social skills. As always, I turned to books to find answers, but my real answers didn’t come until 11 years later.
The books were a great start, helping me type myself as INFP. They gave me an understanding of typical behaviors of other types and how to communicate with them. I special ordered a copy of Gifts Differing which had the medians and stats I wanted but what I didn’t have was practical knowledge.