I just Beat The GMAT!

I started studying in June and after many practice tests (MGMAT and GMAT prep) I was consistently scoring 670-700. I sat in August and score a 600.... completely demoralizing. I vowed to retake knowing I could do much better. I crammed and re-studied all the material and took many more practice tests (Kaplan, MGMAT, and GMAT prep) and went in to the test sure I would score better. The questions were easy but I knew they were too easy. I thought I couldn't of done worse than 600 and then there it was...580. I knew with my work history and undergrad GPA that 600 would get me into most decent part-time programs, but I was disappointed in my score knowing I could do much better. I signed up to re-take one more time and studied only sentence correction and number properties and didn't get all stressed out. I went out the night before and had a couple drinks and tackled the test the next morning. I got a 650... I know I can get do better, but this is good for me!