Reddit reviews The Passionate State of Mind: And Other Aphorisms

I would like to echo the recommendations of Epictetus, who was the teacher of Marcus Aurelius. He wrote no books, but we have two sayings collections written by a student, the Discourses and the Enchiridion (or Handbook); the Enchiridion is just a digest of the Discourses, but includes sayings from the portions that haven't survived.

One modern philosopher who often wrote in a similar format—brief personal reflections in no particular sequence—is Eric Hoffer, an autodidact who wrote philosophy in his spare time while working as a longshoreman. Check out The Passionate State of Mind.