"Between 1968 and 2005 I’ve learned a lot about explaining special relativity. One pedagogical discovery has been especially valuable. Anybody wishing to understand the subject must be able to visualize how certain events taking place, say, in a railroad station, are described from the point of view of a passenger passing through that station on a uniformly moving train and, conversely, how events taking place on such a train appear to a person standing in the station. Without the ability to translate from one such description to another, one cannot begin to understand relativity. But all introductions to relativity that I know of, including my own 1968 book, take the ability to do this for granted. They immediately require the reader to apply this unused, undeveloped, often nonexistent skill to some highly counterintuitive phenomena. In explaining relativity this process often leads to descriptions from two different perspectives, which appear, at first glance, to contradict each other. Faced with an apparent paradox, people who have never before thought about transforming station descriptions to train descriptions and vice versa quite reasonably assume that they must have done something wrong in the transcription. Rather than seeking an understanding of why the contradiction is only apparent, they lose confidence in the analytical technique that gave rise to it. In this respect the pedagogy of the standard approach to relativity is terrible. One introduces a crucial and unfamiliar conceptual technique— changing descriptions from one “frame of reference” to another—by immediately applying it to some unusual and highly counterintuitive cases. The most important thing I learned in teaching relativity to many generations of Cornell undergraduates, none of them science majors, is that one must begin teaching them the technique of changing frames of reference by applying that technique to some entirely commonplace, highly intuitive examples. There are many such ways to develop these skills, and they enable one to learn much that is not at all obvious, though never paradoxical."