On Oct. 8, 2012, the life of Zelda Sondack Ackerman was cut tragically short. She was 100. Zelda Sondack Ackerman was my mother. So I came in for a large dose of the bogus comfort that people are apt to inflict on mourners. “She is at rest,” said the doorman of the Manhattan apartment building where my mother had lived for over three decades. I did not believe that my mother was at rest. I believed that she had — simply and terribly — ceased to exist, and I wondered why the doorman was taking it for granted that I shared his religious outlook. “She looks so peaceful,” said the man who pronounced my mother dead. But she did not look peaceful. She looked dead. Even if she had looked peaceful, she still would have been dead, not peaceful. Being peaceful is a pleasant experience. Nonexistence is not. “She will live on in your memory.” Woody Allen anticipated my reaction to this: I would rather have her live on in her apartment. Most mourners probably get subjected to such treacle. Additional banalities await mourners whose loved ones made it into the triple digits. “Wow, 100 years old!” wrote a contributor to the online guest book that accompanied the paid obituary in The New York Times. Other people told me that I should be glad my mother had lived so long and that, rather than mourn her death, I should celebrate her long life. I celebrated her long life while she still had one. I was at her glorious 100th-birthday celebration, where she received certificates sent from the Manhattan borough president as well as from President Obama, whose second term she was eagerly anticipating. “I’m walking on clouds,” she said the next morning. But no life is long once it is over. You are just as dead at the end of a life that spanned only a century as you would have been if your life had spanned only a decade. And who can deny that your death is just as tragic? Only ageist fools like the author of a recent book about the pleasures and pitfalls of various careers. His chapter on the clergy contrasts “a funeral for a103-year-old man who has lived a good life” with “funerals for small children,” as if the latter deaths would be tragic while the former would not. Why can’t this author see that the end of a century of thoughts and experiences is a great tragedy? Ageism begins while an old person is still alive, of course. “You’re 93? Really? You’re very lucid,” a banker said to my mother seven years ago. “Why, thank you,” she replied. “So are you.” There were also my acquaintances who, upon hearing that my mother was well into her 80s, then her 90s, asked me whether she had any “intellectual challenges.” Rather than pointing out that, if my mother had dementia, I would hardly betray her by telling people about it, I replied that she was striving to perfect her Yiddish — an activity that gave her a thrilling intellectual challenge. Some people got it right. They said things like, “How wonderful,” when I told them that my mother was 90 . . . 95 . . . 99 . . . and “How terrible,” when I told them that she had died. They did not try to prettify death. They had the sense to recognize a simple truth that holds for all of us who love life and do not believe in an afterlife: Death stinks. Felicia Nimue Ackerman, a monthly contributor, is a professor of philosophy at Brown University.