What does it mean that appropriate emotional response matches the situation?

Wise emotional responses are proportional to the actual significance of the event.

Example: A colleague sends a curt two-word reply to your detailed email. You notice a flash of irritation, a narrative beginning to form — they do not respect your work, they never read anything carefully, this is a pattern. Then you pause. You consider the actual significance of the event: someone sent a short email. Maybe they were between meetings. Maybe they were on their phone. Maybe the short reply was agreement, not dismissal. The event, stripped of the story you were layering onto it, is small. Your emotional response was gearing up to be large. The gap between those two magnitudes is the gap this lesson teaches you to close.

Try this: For the next three days, keep a proportionality log. Each time you notice a meaningful emotional response — irritation, anxiety, excitement, offense, dread, elation — write down two things: (1) the triggering event described in purely factual terms, and (2) the intensity of your emotional response on a 1-10 scale. At the end of the three days, review your entries. For each one, assign a second rating: the actual significance of the event on a 1-10 scale given everything you know now. Look for the entries where the gap between emotional intensity and actual significance is largest. Those gaps are your calibration targets — the specific situations where your appraisal machinery is producing disproportionate output.