Growing up in the 1950s, I
remember how my mother, coming home from somewhere where she’d been out, would
go into the bedroom and get unchanged. That phrase has fallen out of use now
but if you’d changed to go out, then it made sense to say that, when you came
in again, you got unchanged. It seems to me now a metaphor for the times. The
default was ‘unchanged.’ That was the norm then.