For the past several years, marketing strategy has reorganized itself around a simple premise. Third-party data is fading. Privacy expectations are rising. The solution, we are told, is first-party data. Collect more of it. Centralize it. Build the customer view around it. In many ways, the shift was necessary. Direct relationships with customers are more durable than rented audiences. Consent and transparency matter. Organizations that invested early in their own data ecosystems are better positioned today than those that relied entirely on external signals. But the industry’s confidence in first-party data has grown so strong that it now obscures a more complicated reality. Owning customer data does not automatically translate into understanding customers. Most marketing leaders have sensed this tension already. Despite increasingly sophisticated technology stacks, many organizations still struggle with familiar questions. Which records represent active individuals?…