Students evolve, for better or worse, through the learning continuum in which any teacher is but one link. Former students, a s teachers, disseminate knowledge they gained from their own teachers. Those from whom we have evolved become part of those who evolve from us. What we evolved from is probably clear to us, but the evolution of those following us is, generally, somewhat murky. We may all cite teaching “successes,” but other students, who do not seem to meet the intellectual demands of science, may actually take away unrecognized value from their experience. Industrial work usually involves informal teaching too; bending talents, technical training, and biases to program goals without destroying the individual qualities is a form of teaching. Our former relations with our own teachers lead us to understand that the young persons we work with perceive our actions and reactions as a cameo of the life they expect to enter. Once we are perceived as a “teacher,” we are a teacher all of the time.