I really enjoyed the format of the book. It was a dialogue between a philosopher and a young man in a Socratic dialogue style. I found the audio version to be excellent.
The book introduces Adlerian psychology and what kind of philosophy can be based on it.
Adlerian psychology seems to deny the effect things from our past such as trauma on our present and future. It arguses that we all use our own (subjective) perspectives to interpret our life and we have the option to choose different perspectives if we have the courage to change.
It also denies certain traits that we think of ourselves as unchangeable "personality" but instead labels it as lifestyle that we can decide freely to change.
The book discusses the importance of accepting oneself and being part of a community. It tries to expand the traditional definition of a community such as a school or work place to include the whole universe.
Adlerian psychology has some common traits with stoicism. For example the book highlights the importance of focusing on ones own tasks that they can control and dismiss any influence we may have on others tasks that we can't control. An excellent example mentioned in the book is "You can take a horse to the lake but only the horse decides for itself to drink."
An interesting point I found was the recommendation to avoid praising or rebuking others but instead focus on encouraging others. The book suggests that praising and rebuking enforces a vertical hierarchy in our society instead of a horizontal one.
Another interesting point was how according to Adlerian psychology humans seek superiority and try to avoid a feeling of inferiority. The book dismisses the idea of living in a competition among others but instead aiming to compare to oneself and think of others as "comrades" instead of "enemies".
I wrote a blog post summarizing the book here.