"Gordon, don't forget this is a RHD car, so the South African version matches."
Oops.... Brain fart, there
The first time I traveled to Ireland on business, I landed at Shannon around 5AM local, got my rental car and headed to Cork on the N20. Of course, I wanted to keep out of everyone's way first thing in the morning, so I hugged my lane, taking it slow. Took a few minutes, a lot of high beams in my mirror and a few horn blasts before it dawned on me that I was in the passing lane doing just below the speed limit. 
Later on, when I was more seasoned as a tourist driver, I realized that, outside of towns where the signs say 30 - 40, the rural posted speed limit is more of a suggestion.......