Although school libraries have changed greatly since the publication of the first set of school library standards in 1920 (National Education Association and North Central Association of Colleges and Secondary Schools 1920), each subsequent iteration of the standards has sought to define the next incarnation of a profession undergoing continual evolution. Four professionals who have moved into different phases of their school library careers offer reflections on how the professional standards influence their work. The first describes how she transitioned from a classroom teacher to a school librarian. The second discusses her career as a school librarian fresh out of graduate school. The third looks at his career as it moved from one state to another. The fourth focuses on his work as a library educator and his research in the field of school librarianship.