One of the most basic points made by Roland Barthes, strongly implied in the series of short essays in the first section of Mythologies, is that anything produced in our culture -- including soap detergent advertisements or popular (now widely called "professional") wrestling -- is worthy of our attention and analysis because these cultural productions can have a complex and important meaning or function in our culture. This point is profound, I think, and has earned Barthes recognition as one of the earliest practitioners of cultural criticism.
In his long essay in the second section of Mythologies, titled “Myth Today,” Barthes also makes a number of explicit, sometimes challenging points. One of his main points is that the linguistic sign system of Ferdinand de Saussure can be extended to include another layer of meaning. According to Saussure, a linguistic sign is made up of the signifier (the word that we say) and the signified (the thing that we mean when we say the word):
--- = sign
Barthes says that the sign itself (including the original signifier and signified) acts as the signifier on a second level of meaning, the mythic level. On this mythic level, the original sign acts as the signifier and is paired with a new (and more abstract) signified. This second pairing, Barthes argues, is not arbitrary. It serves clear ideological purposes, such as supporting the values of the ruling class. (At the time that Barthes wrote Mythologies, he was strongly influenced by Marxism. At a later stage in his career, he moved away from Marxism toward post-structuralism, which makes his later works – in my opinion – fascinating but even more challenging to read.)
A second explicit point that Barthes makes in the essay “Myth Today” involves what he calls “inoculation.” Barthes argues that a little exposure to criticism (such as the handwringing that we see on TV when people talk about how the cost of college is increasing at something like three times the rate of inflation) can essentially blind us to the larger, related injustices of the systems in which we live (such as the enormous disparity between the haves and have-nots in the United States).