To tell the truth, when I came to Yorkshire, I couldn't distinguish between a basic Yorkshire and a basic Lancashire accent. Nowadays, I can distinguish between Bradford, Dewsbury, Sheffield, Harrogate, Barnsley accents etc
Also, when I came to Yorkshire, I struggled to distinguish between the Somerset Yokel accent and the Gloucester Swedebasher accent. Obviously I've still never bothered to learn.
To be honest I can't tell the difference between west country accents either. I have a mate from the forest who when he has had a few it is virtually impossible to understand all but smattering of words.