Forty is the old age of youth; fifty the youth of old age.

Middle life is not one thing. Looked at from one side it is the end of being young, and from the other it is the beginning of a long stretch that has its own shape and its own vigour. Both are accurate, and which one you are living in depends on which way you are facing. Something is genuinely lost at that turn; something else has not started yet.

If you are somewhere near that line, notice which way you habitually look. Grieve what is actually gone rather than the whole of it. Then ask what the next stretch is for.