Summary
This quote suggests that "A Christmas Carol" is an inherently successful and well-crafted story, implying that it is difficult to negatively impact or ruin its core attributes. It suggests that regardless of interpretation or adaptation, the story's elements such as themes, characters, and plot are so strong that it always manages to captivate and resonate with audiences. The phrase "fool-proof" implies that the story's overall quality and appeal make it nearly impossible to mishandle or cause it to lose its impact.