This book tries to show, by reviewing the history of Brazilian public libraries, that they could be a totally different institution from the ones we know today. The history of these libraries is full of mistakes created and reinforced by public policies based on common sense and contrary to the information needs of the population. This framework produced a format of Brazilian public libraries which, besides being precarious, develop a standard of common services dissociated from the real information needs of its population, making this institution strange to the Brazilian citizen, especially to the worker. However, with the correct development of public policies, carried out with transparency and broad participation of society and librarians, it would be possible to transform the current Brazilian public library into an essential institution to society. This library would then be active in reducing social inequalities, in the social and economic development of cities and municipalities, in the professional and cognitive development of citizens and in strengthening citizenship. Have a good adventure!