Most of my professional life is about incremental improvements. Typically, I take students who already are the successes of our education system, and I make them slightly more successful. Or I slightly improve the body of known mathematical research by proving a new theorem. I rarely do anything of great importance. This is not to say that I am not important—somebody needs to do my job. But—really—I am a cog in a machine. Moreover, I am a replaceable cog, in that people’s lives would not be all that different if I were replaced with a similarly competent professor.
Almost every day of my work life is like this, and I am fine with that. But not yesterday. A student came to me asking for advice. This student had two choices, and the choice would dramatically affect (at least) the next ten years of the student’s life. I gave this student advice that no one else had given before, even though many were asked.
It is rare that I have an opportunity to change the course of one’s life. It was completely satisfying.