Lloyd first reviewed previous scientific works on analyzing dreams, which he thought was interesting but not sufficient. Then he described many dreams to clarify his theory. His method started by analyzing his dream "Irma injection", but there are also many case studies from patients, and many of the most important dreams cited in the book come from others.
Many sources of Freud's analysis come from literary works, and the book is more of a conscious attempt at literary analysis, surpassing the elements of psychological research. Here Freud first discussed the later developed Oedipus complex theory, that is, the Oedipus complex.
In the book, the author claims that he has discovered three major truths: dreams are the disguised satisfaction of unconscious desires and childhood desires; Oedipus complex is a common human psychological emotion; children are sexually aware and motivated.