Really? is it like the GCSE? cos im in luck... i got an A* for economics in GCSE...
I think there are only a few schools in the uk that offer economics at GCSE and my school did that.
Also i agree with really needing logic and common sense, with good reasoning skills. Because to be honest i didnt study all that well for my GCSE exam... and during the exam and i didnt use many economic terms but really used my common sense and logic to figure out suitable ideas and solutions.
However in my first lesson in a-levels, i have a few friends who didnt take Economics at GCSE and they were bamboozled by all the terms in the first lesson. But i think you shouldn't be intimidated by that because when you learn the terms you should be able to do fine.