Thanks everyone for all your advice - and support!
I've absorbed it all and will follow your wise words.
I don't intend to try and impress, as I know my limits and am aiming to go for stamina, rather than speed, I guess that honesty is the best policy and admitting your gaps in knowledge is far better than behaving as if you know the score and falling flat on your a$$ (quite literally!).

Sadiekate - our roads have a strange and wonderful numbering system, which is a mystery to everyone but the city planners. "A" roads are major roads (often dual carriageways, but not always), while "B" roads are quieter, more rural roads - windy-bendy country roads. Of course, this is not always the norm. The A167 can suddenly metamorphosise into the B123, only to become the A138 and then continue as the A167 as if nothing had happened!
During the war we also took down all our road signs to confuse the Germans if we ever got invaded. Unfortunately, it seems that no-one ever remembered to replace them, so a trip out is often a magical mystery tour!
I kid ye not! We also have "C" roads, but no-one ever talks about them!

A century to me would be miles - 100! Metric? Spit spit, we must resist metric to the death! In the 70s we were all forced in school to suddenly become metric - our currency changed and so did our measurements. I'm now kind of in limbo as I understand centimetres (inches are a mystery!), but can only judge in feet. I understand the bottom half of centrigrade and the top half of farenheit! And our weight is measured in "stones"!! One stone is 14lbs! Everyone usually will express their weight as 8stone 7 or the like, lbs are for our yankie cousins, kilos are for those weird Europeans!

Glad I made all that clear for you!