Bartlett makes a point that is easy to understand and hard to apply: almost nothing important happens in one dramatic moment. What look like overnight successes are actually the accumulation of hundreds of small, invisible decisions made consistently over a long period. The reverse is equally true. What looks like a sudden collapse is usually the accumulation of small misses that nobody noticed in the moment: the meeting that ended slightly poorly, the habit that slipped for one week, the commitment that was kept in letter but not spirit, the feedback that was not sought. He calls this compounding. Just as money compounds through consistent investment over time, so do decisions, behaviours, and standards. A person who consistently does a little more than expected compounds into someone remarkable. A person who consistently does slightly less than expected compounds into someone unreliable. The problem is that each individual decision seems trivial. Skipping one training session does not make you unfit. Letting one promise slide does not make you untrustworthy. The single instance is almost invisible. But the pattern of the instance, repeated hundreds of times, is everything. Bartlett argues that the most important question is not 'How important is this specific decision?' but 'What kind of person does making this decision make me?' The answer to that question accumulates over time into who you actually are.