Why do people sacrifice their lives for a country or a cause? When I saw a "Zero" fighter aircraft and a salvaged Kaiten (Return to Heaven) midget submarine exhibited at the Yamato Museum, Hiroshima, I knew they were vehicles for suicidal missions from 1944-1945. Many Japanese pilots or submariners, as well as their opposite combatants, sacrificed their lives to preserve the respective groups' survival.
I learned from ancient Chinese literature that "Death can be heavier than Taishan (Mountain) or lighter than a feather." The 19th Century Japanese Imperial Rescript to Soldiers and Sailors goes further :"Duty is heavier than a mountain; death is lighter than a feather." During the World War II in Japan, there was also a saying that: "Some sakura petals will fall and so will the others."
From the Museum exhibits, I read about the suicidal note of the officer who pioneered the Kaiten strategy and actually took the lead to showcase to followers. From another Kamikaze documentary, I learned that dying was seen by the pilots as the ultimate fulfilment of their duties and it was the most meaningful thing to do. Those who missed the opportunity to sacrifice themselves had cheated those who went before them and would not get infinite glory.
"But there was nothing to celebrate." Embarrassingly recounted by a selected kamikaze pilot Takehiko Ena in a 70th anniversary of World War II documentary. The dead could not resurrect to re-engage with their loved ones and the future they foresaw could be very different eg the destructive impact of kamikaze when compared to the atomic bombs. While the past is over and done with and life is beautiful yet fleeting, we had better learn from history and create a better future for all!