Plato's cosmology and theory of the human body, and the story of Atlantis; courtesy of a phantastic audio version featuring David Rintoul as Socrates, David Timson as Timaeus, and Peter Kenny as Critias.  Philosophical and scientific enquiry redolent with the joy of the intellectual exercsie for its own sake -- that alone makes it a joy to tag along (however much Plato might be distressed to learn that his theories on the human body have at long last, after some two millennia. been proved wrong after all -- and despite his warnings about the falliability of the human mind, even by scientific experiment).

(Task: Read a book about philosophy or a philosopher, or a how-to book about changing your life in a significant way or suggesting a particular lifestyle (Hygge, Marie Kobo, etc.).