While McIlroy's astonishing eight-shot victory at Congressional last year marked him out as the heir apparent to Tiger Woods, he readily concedes his mindset could have been more realistic going into the Masters earlier this month.
The opening Major of the year was widely billed as a two-horse race between Woods and McIlroy, two of the most exciting players in the game, but the pre-tournament favourites ended a disappointing week in a tie for 40th place.
"Going into majors as a Major champion, it definitely heightens your expectation levels a little bit," world number two McIlroy said.
"That was something that I didn't control so well at the Masters a few weeks ago. Going back to defend my title in San Francisco will be a great experience for me and something I am really looking forward to.
"You try and approach it like you would any other event, just prepare as best you can and go out there and try to play the golf you know you are capable of."
McIlroy, who at 22 became the US Open's youngest winner since 1923 with his record-breaking victory at Congressional, relished being bracketed with 14-times Major champion Woods.
"If I am being compared to him, I am doing something right," the mop-haired Northern Irishman said. "I know there was a lot of hype pre-Masters about it being a two-horse race or whatever and it was a two-horse race for 40th.
"It wasn't our best week and hopefully, going into the next major, we both play a little bit better. It would be great if we could both get in contention on the Sunday."
McIlroy posted a tournament record total of 16-under-par 268 at rain-softened Congressional last year but he predicted a much stiffer, and more typical US Open, challenge at Olympic Club from June 14-17.
"The thing that made the scoring low last year was the fact they got so much rain before (the tournament)," said the 22-year-old from Holywood in County Down.
"Something around even par isn't going to be too far away. Last year was a little bit of an exception but I think this year if you shoot four 70s, you will have a great chance."
McIlroy described his 2011 US Open victory as "a life-changing experience", one that elevated his status among his peers and made him hungry to add further Major titles to his already glowing resume.
"You always dream and hope one day that you will be able to do it and to make that dream become a reality is something that was something very special," he said.
"It puts you among an elite group of players that can call themselves Major champions. It probably makes people view you a little differently and maybe you gain a little bit of respect from guys that have won majors. You've joined the club.
"If anything, it just gives me more confidence in myself knowing I could win on the biggest stage in golf. Knowing that I have done it before, it gives me confidence to think that I will be able to do it again."