It's a measure of your ability to assimilate instruction and replicate it to the satisfaction of your instructor. It will determine how much of a training-risk you pose, which in turn tells the system if it should invest in putting you through an arduous and expensive course. In short "Monkey see, monkey do."
On a lighter note, the hours all count towards the requirement for PPL(A), and it serves as a good introduction to a career full of women throwing themselves at you. Relax, talk to your stick-monkey trainer, and if you don't understand any instruction you are given, ask.