Fair enough. And if I'd lived in Nazi-era Germany then I might perfectly well still have that instictive fear of people wearing long coats.

But I've never lived in Germany, or in the Nazi era, let alone both at once, and this is also true of almost everyone else I associate with; out here in the free world we've always been able to wear coats of whatever colour and length we feel like (except in American high schools recently, which also doesn't apply to many of my friends). So I'm sure that isn't the whole story of why we instantly associate long black coats with the Gestapo. I'm still puzzled.

Watching too many episodes of 'Allo 'Allo?

It's not just the clothing, but how it's worn, and how the person moves. You do look quite sinister walking around in that coat...