When I was growing up in the 1970s, I would not have given much thought to fashion for the over-50s and what I might wear if I had the good fortune to live to see such obscene decrepitude. But if I had, I would have imagined wearing what my late grandmother called “slacks” (elasticated-waist trousers), long-line ribbed cardigans with large ornate buttons and comfortable shoes from Clarks.