The particular grief of watching your parents age into people you barely recognize, while everyone around you keeps calling it the natural order of things

The phrase natural order of things does more damage than almost any other piece of inherited wisdom. It gets offered up at dinner tables and in hospital corridors and over the phone by well-meaning cousins, and it is meant to close a conversation rather than open one. What it actually does is tell you that the specific grief you are carrying — the grief of watching a parent become someone you no longer recognize — is not a legitimate thing to mourn. It is just what happens. Everyone goes through it.