On the day of my test I had my lesson and pulled up outisde the test centre carpark to pass a couple of minutes before my test was due. Casually my instructor asked me to recite some number plates and pointed at a car, I said "I can't read that from here, no chance!"

She said "Erm you must be joking? That is less than the required distance to pass your test!"
Arse was my first thought, something relatively out of my control - you get taught all the driving skills and you know when you are ready but to be let down by your eyesight on the day of your test was a right bugger!
Fortunately my examiner didn't test it from the full distance and I just about passed!