Winning the U.S. Open in June... it still seems surreal. When I was growing up, I wanted to win that tournament so badly, and now that I have, I'm still trying to come to grips with the long road it took to get here. I've had incredible experiences this season—it's been a real breakthrough for me. Besides winning the Open, I won another LPGA Tour event (the Lotte Championship), finished second in the season's first major (the Kraft Nabisco) and third in two other events. So why now? Why, at age 24, almost nine years after I turned pro, am I playing my best? Well, a lot has changed about my game and my attitude toward golf. In talking to my coach, David Leadbetter, we believe it's a combination of factors that has made the difference—five, to be exact. We'd like to share those things here, in hopes that they can do for you what they did for me. What I've learned from my turnaround can be summed up in a quote from Winston Churchill: "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."

1. I'M LOVING HITTING DRIVER
This year I'm really taking advantage of my length off the tee. I used to pull out a fairway wood or hybrid on tight holes, but I've reached a point where I don't care that I'm not going to be that player who hits 14 fairways. I'm going to be in the trees sometimes. But as long as my drives go somewhat in the right direction, I'm good with that. And besides, I'm not so bad out of the trees.

LEADBETTER: The lesson for the average golfer here is, swing your driver with confidence—and that means let it fly. If you trust your driver, the distance you'll gain will translate into shorter approach shots. Michelle went from hitting 69 percent of greens in 2013 to 77 percent this year. More greens in reg means lower scores.

2. I'M PHYSICALLY STRONGER
I used to think I had strong legs, but when I started working with my trainer, David Donatucci, we found that wasn't true. I was a long hitter when I was young, but my lack of lower-body strength made me inconsistent. So I really got focused on making my legs, glutes and hips stronger, and now my swing is more stable. That means I can consistently hit the ball hard. I don't have to force myself to get into good positions. Now it comes naturally.