one thing i will say is that i picked some of the harder a levels (maths, physics, history, economics) in the mistaken belief that unis would judge the difficulty of the course..
this really isn't the case, and i wish i'd done easier ones to get higher grades. still, it's not the be all and end all if you make a mistake like this at a level- there are 2nd and 3rd chances, and in terms of career ambitions i'm still on the same track as if i'd gotten AAA.