A delightful adventure
Originally written in 1949, this book has become a classic, wielding an influence at least as great as that of Sir James Frazer's The Golden Bough. Many prominent people have admitted being influenced by it, including filmmaker George Lucas, who read it after completing the draft of the first "Star Wars" movie and went back and revised his screenplay to more-closely follow Campbell's ideas.
Campbell's thesis was that all cultural and religious myths were basically the same; that is, they generally conformed to a universal model, which Campbell claimed has remained remarkably constant throughout mankind's history. Campbell also agreed with Sigmund Freud and Robert Graves that myths are deliberately disguised, so that only the enlightened understand them. What we see superficially as an astounding story contains a deep, fundamental concept of mankind's most basic nature.
As an explanation of why this universal aspect exists, Campbell further maintained that we all have hero-dreams that follow the same pattern: we are alone, we come upon a major obstacle, we overcome the problem, either through our own efforts or by the help of another, and suddenly find great peace and contentment. This is the universal hero-saga and any story that adheres to this outline will (properly told) strike a universal chord of sympathy.
Campbell was extremely well-read and the book is a treasure-trove of folkloric anecdotes. One could call it a one-volume education in mythology. it is also beautifully written, with the grace of a poet and the skill of a masterly storyteller.