I think in modern society, many individuals suffer from from a existential problems. Many have a lack of purpose, and question why they're here, and what's the point. This leads to a lot of irrational anxiety and fears over things, such as death. Things that are largely out of the control of most individuals. In historical times, first off, the life expectancy was much lower. When you're surrounded death, you become indifferent when it happens, and you're not all that worried if it happens to you. Secondly people in historical times had a lot less distractions, and most peoples lives were made up of core activities and goals. Such as: Providing shelter, food, clothing, protection for ones family. People had more singular focuses and didn't really have time to dwell on uncertainty. Thirdly, most of the world in historical times were highly devoted to god and the afterlife, thus they really didn't fear death because they were convinced a better place was awaiting them upon it happening.