What does it mean that invalidation is more informative than validation?

Finding out your schema is wrong teaches you more than confirming it is right.

Example: You believe you are bad at public speaking. For years, every stumble at the podium confirms this schema. Then a colleague records you giving a spontaneous hallway explanation of a complex topic — clear, confident, compelling. One disconfirming instance does not just dent the schema. It restructures it entirely. You are not bad at public speaking. You are bad at performing scripted presentations under pressure. That single falsification is more informative than a hundred confirmations ever were, because it forces you to replace a coarse model with a precise one.

Try this: Identify a schema you hold with high confidence — a belief about yourself, your industry, your relationships, or your capabilities. Write it down as a clear proposition. Now design three specific observations or experiments that could falsify it. Not tests that would confirm it — tests that would break it. For each potential falsifier, write what you would learn if the schema failed the test. What replacement schema would the failure point toward? This exercise trains you to seek the disconfirming evidence that teaches you the most.