There is always one. For some parents it is the year the child was three and would fall asleep on your chest in the afternoon. For others it is the summer they were nine, when the family bike rides finally worked and nothing had cracked yet. For others it is the long dinner-table years of middle school, when the kids were old enough to talk and still young enough to want to. The phase you grieve when it ends is not necessarily the easiest phase — often it is one of the harder ones, in the middle of which you were exhausted and complaining. But in retrospect it has the texture of a country you used to live in. You can describe the smell of the kitchen, the configuration of the couch, the songs that were playing. And it is gone, in the specific way that lived phases are gone: not because anything bad happened, but because time advanced and the bodies changed and what was possible then is not possible now.
The grief is real and rarely named. We have public vocabularies for the deaths of people, the ends of marriages, the loss of jobs. We do not have a public vocabulary for the end of a developmental stage in a child who is still alive and well and across the table from you. Pauline Boss calls this ambiguous loss: the loved one is present but a version of them is gone. Your seventeen-year-old has not died, but the four-year-old has, and you are the only person in the world who remembers the four-year-old in full sensory detail. Their friends never met that child. Their teachers don't remember. You are the archive. The archive is also the mourner.
The grief tends to arrive unevenly. It bypasses the predictable dates and ambushes you at unrelated moments — folding a shirt that fits a teenager and recalling that this same body wore size 4T, smelling the sunscreen that you used at a beach you no longer go to, hearing a song that played in the car ten years ago. The pattern of the grief is one of intermittent recognition. Then it recedes. Then it returns. It is not pathological; it is the mind doing what it does with discontinued love-objects that have not disappeared but have transformed.
The phase you grieve is often the phase where you felt most fluent as a parent. You knew what the child needed; you could do most of it; the gap between what was required of you and what you could give was narrow. Later phases require different competencies — many of them you are still learning. The grief is partly for the version of yourself who was good at the job, before the job changed. You are not grieving only the child who was; you are grieving the parent you were, who matched that child, in that house, with those rhythms. That parent doesn't exist anymore either. The new parent — the one trying to help a teenager with a college application, or text a young adult appropriately — is a beginner again.
The healthy practice is not to suppress the grief and not to dwell in it. It is to let it visit, to name it when it visits, and to let it pass. The unhealthy patterns split in two directions: the parent who refuses to let the phase end, by infantilizing the older child or by retreating to nostalgia, and the parent who refuses to feel the loss, by hardening into pragmatism and treating the grief as indulgence. Neither serves anyone. The parent who lets the grief visit can be fully present with the current version of the child, because the previous versions have been honored rather than buried.
It also helps to remember that you are mourning while the source of joy is still in the room. The grief for the four-year-old does not displace the love for the seventeen-year-old; it is parallel. The teenager standing in your kitchen is having their own current phase, which you will grieve in ten years and which is right now still happening. The discipline is to be in the current phase enough to register it, so that future grief has something to grieve. The parents who are present for each phase as it unfolds tend to grieve more deeply later — because they actually saw what they had — and also tend to suffer less, because nothing is left undone.
The Fifth Law applies: you revise your model of the child, of yourself, of the family, as each phase ends. The revision is not betrayal of the previous phase. It is the only way to honor it, because the previous phase was real, and so is the next one, and only by letting the first go can the second arrive in full.