"Training" certainly fit the factory model of education. To others, the word conjured images of what one does to animals, getting them to sit, roll over, and play dead. Few educators now describe their learning experiences as training. The word "development" may be an improvement, but just a small one. It evokes images of what someone does to someone else: develop them. In education, professional development has, in fact, often been what someone does to others. The back-to-school speaker holds forth in order to motivate the teaching staff for the coming year. The specialist arrives from the capital to increase teachers' knowledge of state standards. The university professor advances the careers of educators through courses that offer credits to move them up on the salary scale. Such development activities as these (and even some training activities) are neither bad nor wrong. In some cases they are vital to professional and organizational growth. They are not sufficient. If all educators needed to do was develop (i.e., grow, expand, advance, progress, mature, enlarge, or improve), perhaps development would be enough. Educators often find that more and better are not enough. They find they often need to change what they do, on a daily or sometimes hourly basis, as they respond to the needs of the learners they serve. Doing this takes learning. It is clearer today than ever that educators need to learn, and that's why "professional learning" has replaced "professional development." In this article, the author argues that developing is not enough. Educators must be knowledgeable and wise. They must know enough in order to change. They must change in order to get different results. They must become learners, and they must be "self"-developing. (Contains 10 endnotes.)