Why is it so hard for people who hold this view to see that there is a bootstrap problem for any knowledge beyond personal experience if this were true? The rea

Why is it so hard for people who hold this view to see that there is a bootstrap problem for any knowledge beyond personal experience if this were true? The reality is that definitions are works-in-progress, and getting started often involves a 'definition' that is little more than a placeholder for an eventual explanation of something currently unexplainable.