Again, that is probably less true than it was. I used to be able to tell whether someone came from North or South of the Thames ie Essex London or Kent London but I doubt whether that would be easy now.

It probably got reassembled incorrectly when it was beamed through hyperspace in the post transporter! 

But are those jacket potatoes done in an environmentally sound way in the microwave or baked for several days in the oven?

It matches my experience. I've lived in the North East for years now and to me Geordie sounds normal (though oddly I don't seem to have absorbed any of it myself   ). When I go home to visit family in the West Midlands, everybody sounds foreign to me. It's quite a relief to step off the train in Newcastle and hear normal speech again  

I can't remember any specific point when I noticed the people in Newcastle sounded like they were speaking "my" accent, but that's what must have happened on some subconscious level.

Sorry, I should have added to that story.  Mum's now been living in roughly the vicinity in which she spent her later childhood (the Bracknell/Wokingham/Reading area) for six months, and despite the fact that her accent is now somewhat on the hybrid side, she hasn't yet had anybody pass comment on it - unlike in Durham where it was regularly mentioned.

The other thing I found about my accent when growing up in Durham was that "anything southern" accent-wise was seen as "posh".  Mum was baffled by this particularly - she's less RP than I am, and certainly doesn't talk posh, but this is how she was judged by people in general.

" I also find it interesting that some people immediately pick up the accent of wherever they happen to be living".

I have a tendency to veer off into the accent of the person/persons that I am speaking with. Many moons ago I worked and shared a flat with girls from Oop North. By the time I moved out my original accent (I`m a Southern girl) had all but vanished!  Even now, if I get a tad overexcited about something I find myself sliding into `North speak`

Well, Baz, bearing in mind that English as a language we'd recognise didn't exist at all in Hadrian's time, that can't be it at all, and you are right to say that you were wrong. If you bear in mind that Caesar considered Britain as part of Gaul, and that the very name 'Gaul' is cognate with Gaelic, then the chances are that at that point there were no separate tongues, or that if there were, they represented the two branches of the Celtic language: the 'P' or Brythonic line, which includes Welsh, Cornish and Breton, and the 'Q' or Goedelic strand - Irish and Scots Gaelic. To confuse matters still further, what we think of as Welsh was spoken much in of Scotland not only in Hadrian's time, but centuries after.

You're also right to point out that they're not two different tongues: you're looking at two points of a rainbow of shades that blend imperceptibly. The whole of the east coast from East Anglia upwards has sounds and words which are influenced by the Scandinavian raiders we know as Vikings, and whose heavy reliance on dipthongs can be heard still in vowel sounds from the Midlands through Lincolnshire and Yorkshire up through Geordieland to Berwick and beyond: the Gaelic influence doesn't really kick-in until you reach a good deal further west and north. The 'sounding completely different' is a result of the very different sounds that have been inherent in each particular locale for centuries, further influenced by geographical conditions.

Until the recent explosion in mass communication and travel, most regions of the UK, let alone the smaller communities within them, were much more inward-looking. People moved around far less, and language developed along its own lines in each closed area, forming a succession of centres where the language was recognisably different from those adjacent, but nonetheless had flavours of its neighbours . This is evening out more and more, but your choice of Berwick displays a phenomenon really already discussed here, which is that whichever point on the rainbow you decide to examine, it will always represent a transition between one recognisable colour and another.

Careful, Oz! next thing you'll be telling them that 'Big' Ron is only 5'2" tall. (But I do appreciate you not mentioning that at first hearing some people take my accent for eastern European.)