The death of really old people.
Imagine getting so much further than anyone else in defying entropy.
Struggling through gradual relentless decreptitude.
Clinging on to life year on year.
Seeing friends and relatives die before you and reminding you of what’s to come.
Your memories and experiences becoming a distant fog, and then you die.
80, 90, maybe over a 100 years of life, all vanishing into dust. So much time passing, and then gone in a blink of an eye—may as well have never been born at all.