And then I scream when he punches me. I screamed, not because it hurt, but because I saw on my internal video that screaming was the appropriate response. If the internal video would have been different, I would have reacted differently. It is very common that people copy middos in this way from their parents, teachers, and favorite television characters. This is where the mitzvah system comes in to play.
Mitzvahs are commercials which cultivate appropriate internal videos.
Eah mitzvah develops a different aspect of human behavior. Mitzvahs create appropriate internal videos even if we aren't aware of the proces, although being aware of the process accelerates it and permits us precise control over exactly how we want the final video to look. Item C above is thrilling, for it accurately implies that human character is malleable. We can also plant, deeply in our personality, any positive pattern of thought, speech or behavior. There is even more to be thrilled about, however.