In trying to explain why Hong Kong of China ranks highest in life expectancy in the world, we review what various experts are hypothesizing, and how data science methods may be used to provide more evidence-based conclusions. While more data become available, we find some data analysis studies were too simplistic, while others too overwhelming in answering this challenging question. We find the approach that analyzes life expectancy related data (mortality causes and rate for different cohorts) inspiring, and use this approach to study a carefully selected set of targets for comparison. In discussing the factors that matter, we argue that it is more reasonable to try to identify a set of factors that together explain the phenomenon.