UPDATE: I submitted a more formal version of this article to the UMAP Journal (Undergraduate Mathematics and Its Applications), which publishes articles that use mathematical modeling for real-world problems, often with a pedagogical or expository angle. A preprint is available on arXiv at: https://arxiv.org/abs/2603.19945 Five-year survival might be the most misleading statistic in medicine. For example, suppose 5-year survival for a hypothetical cancer is What can we infer from these statistic