The last clear memory of a person is not necessarily a fair summary of them.

The final image tends to dominate. Illness, decline, a last difficult conversation, the version of someone at their least themselves, and that becomes the picture that arrives first whenever you think of them. It is a matter of recency rather than accuracy, and it can quietly displace forty years of a person you knew well.

If that has happened, try deliberately calling up an earlier scene, a specific one, and let it stand alongside the last. Talking to someone who knew them in a different decade helps too. You are not denying the ending, only refusing to let it be the whole account.