Transatlantic flights are unflattering. Hairstyles flop. Makeup melts away. Faces shrivel or swell from dehydration, and contact lenses give way to spectacles.
For a very long time, loyalists were often left out of patriotic American histories of the revolution. Or they were caricatured as upper-class Tory reactionaries, or - rather like the Jacobites - made the subject only of nostalgic antiquarianism.
In the twentieth and twenty-first centuries, products and tastes developed in America have increasingly influenced lifestyles in Europe, whereas in previous centuries, it was generally the other way around.
In Britain, British history is naturally a mainstream subject. Step outside your own narrow specialism, and you can find yourself treading on someone else's toes. But in America, British history is an eccentric, minority pursuit, and while this can be intellectually isolating, it also permits extraordinary freedom.
The argument that any income redistribution is tantamount to socialism, and that socialism has always been unAmerican, has helped legitimise keeping taxes on America's very wealthy very low.
Had Barack Obama been obliged to take his degree at the University of Akron, say, it is doubtful that his progress would have been remotely as stellar.
