The Thought Thinker is a Loner Girl is volume one of the series On Being.

On Being is an astrological, metaphysical, self-referential, self-psychoanalytic case history, narrated in first person by the protagonist Ana, who is the real life author J. Guzmán. On Being is the evolution of J. Guzmán's consciousness throughout Time, and it is meant to aid in astrological research and study (and those of other disciplines like psychology and philosophy). A detailed explanation of what this entails can be found on her website. On Being is open-ended, in that it will continue until the death of J. Guzmán.

On Being is not a series about how to use astrology correctly. It does not directly explain or outline its concepts, theories, or symbols. Rather, it is the raw data in the form of archived diary entries that an astrologer can use to apply practically astrology's techniques for investigative and teaching purposes. If you have Ana's birth information and her compiled life history including dates, times, and locations, you can see how the astrology works systematically in the background. Ana discovers astrology in book nine, and comes to use it to aid her self-psychoanalysis.

In volume one, The Thought Thinker is a Loner Girl, we meet Ana. She is an introverted, self-deprecating teen girl, trapped in a culture she despises – middle-class America's suburbs and public schools. She examines her struggles with identity and mental health as she finishes high school and prepares to enter college and play on the women's soccer team there. She describes an internal conflict omnipresent in adolescence, highlighting themes such as drug and alcohol use, existential despair, self-doubt, insecurity, and the formation of a personal philosophy and spirituality.