That's what NRE does. At least, with me, a new crush will suddenly obliterate all other thoughts, including thoughts about work, and other partners. Nothing seems as interesting or as shiny as SHE does, in all her glorious wonder.
Here's how you deal with it-- get to know her as a person. Right now, she is a pretty face, a kind smile, and a blank canvas on which you can write your most perfect possible partner. She reflects you more than her own self. Learn her. Find the aspects of her character that don't appeal quite as much. Since you're both on good behavior right now, that's going to be hard, but focus on it. Learn her flaws, her quirks, and ways she can be difficult.
Once you really start to understand her as a whole person, the shiny will fade, and you will be able to go back to your normal, sane headspace. (That's also where you can start to really connect, on a deep heart level, and build solid bonds.) Only when you get there, can you start to evaluate how you really feel about him.
Unfortunately, I have to hit the 6 month mark with someone before I start getting my head on straight.