When I did my GCSE's I didn't revise or care about them. I spent all my free time learning how to program, I ended up with DDDDDEEFF. I remember people making fun of me. But i learnt lots of programming skills and within the first month of everyone going to Sixth Form I landed a SE job contracting 370 quid a day. The reply I got when I posted my first paycheck on facebook, lol it went something along the lines of "LIAR" "YOU ARE A RETARD" "YOU FAILED GCSE YOU FAILED LIFE" and everyone thought I lied until I bought my first car, a 35G Scirocco so I mean grades don't mean shi*
Don't follow the sheep people. Pythagoras theorem is not going to get you a job.