Somewhere Towards the End

All through my sixties I felt I was still within hailing distance of middle age, not safe on its shores, perhaps, but navigating its coastal waters. My seventieth birthday failed to change this because I managed scarcely to notice it, but my seventy-first did change it. Being 'over seventy' is being old: suddenly I was aground on that fact and saw that the time had come to size it up.