Just think about results day when you open that brown envelope, and you don't even need to look at the results on the white paper to already know that you got A/A*.
And how will you know that?
Cus you revised night and day... you didn't watch tv, didn't go out, didn't procrastinate on tsr, didn't sleep in the middle of the day, didn't take a 1 hour break from revising cus u were too tired...
then think about the rewards...
the satisfaction of getting the best grades you possibly could, the knowledge that your grades will take you that much closer to getting into that college/ uni/ career you wanted to get into, the happiness you'll feel over not being like one of your friends who's too ashamed of her results to tell anyone, the money/ presents you'll get from friends and family (sorry if this doesn't apply to you),
so work hard now and reap the rewards later