John Dewey was a famous 20th century philosopher who greatly influenced American education. He believed that the only worthwhile knowledge was information that could be used, and considered it pointless to memorize useless facts. Dewey felt that schools should teach thinking processes and skills, rather than just facts. As a result of his influence, schools now teach a broader range of subjects and skills beyond academics, including things like driver's education, cooking, sex education, behavior control, music, science experiments, and democratic principles. Kindergarten classes now include some early academic topics like letters, numbers, colors and shapes, as most children entering kindergarten have already had experiences in preschool or day care settings.