McIlroy also gave some of the credit for his performances to his tennis star girlfriend Caroline Wozniacki, who he says has been a positive influence on him.
"Seeing how hard she works and how hard she practises and how dedicated she is, it definitely flipped a switch with me that I could be a little more like that," he said.
"She's definitely been a great influence on me. I've always felt like I've been dedicated to the game and I've practised hard and I've worked at it.
"But I guess over the past 18 months, especially after winning the US Open, I sort of felt like I went to the next stage of my career.
"I feel like my personality away from the golf course hasn't changed, but definitely when I get to the golf course I'm maybe a little more professional, a little more business-like.
"I guess that's just the way you have to be to be successful and to try and win as many tournaments as you can. It's definitely helped and obviously helped me to win more tournaments."
