John Krasinski tells us why he's worn out -- The ''Office'' star talks about the NBC sitcom and his role in next month's ''Jarhead''

We rang up John Krasinski, 26, who plays long-suffering normal dude Jim on NBC’s The Office (Tuesdays, 9:30 p.m.), expecting to find that all the glory of being on a critically adored TV show had gone to his head. How shocking, then, to discover that the boy can’t even fakehaving an ego for very long. (”I am a huge star!” he blurts. ”I could be making hundreds of dollars!”) But he may be well on his way: He cameos in Jarhead, the Gulf War film starring Jake Gyllenhaal (out Nov. 4), as well as in Christopher Guest’s now-shooting For Your Consideration, and he intends to make his screenwriting debut with an adaptation of David Foster Wallace’s 1999 book Brief Interviews With Hideous Men, which he hopes will start shooting next spring. Here, in his own words, how one nice guy is finishing first.

Almost screw up your Office audition I was sitting in the waiting room, and in the front door comes this guy, and he’s eating a salad, and he’s like, ”Hey, are you nervous?” And I said, ”A little, but I’m really nervous for the people who are making this show, ’cause there’s always a tendency to screw it up…” And the guy goes, ”I’m the executive producer. Nice to meet you.” And I was like, ”Yeah! Should I leave now, or should I walk into the room and then leave?”

Persuade Wallace’s agent to let you make a Hideous Men movie I called the agent and asked, ”Could I ever get the rights for this?” And she was like, ”Aw, that’s cute. No.”… And I said, ”Listen: He writes unlike anyone else I know. The only thing I’m trying to do with this movie is bring David Foster Wallace into more people’s lives.” And she said, ”Well, I’ll let you know next week…but my answer’s not no anymore.”

Make an impression on the director while filming the movie Jarhead I improvised to get Jake [Gyllenhaal] laughing. [In the scene] I’m writing a letter, and Jake read it out loud, and [director] Sam Mendes came in and said, ”That’s the script for the rest of the scene.” And then Sam called my manager and said, ”Would John want to come back for another scene?” I got down there, and he said, ”Here’s the scene: You’re in the middle of a war scene and I need a little comic relief. So, can you go write four or five pages, and I’ll cut it down to two?” And I was like, ”Wait. I’m writing this? Hold on…”

Be humble, dammit I’m not claiming to be a triple threat, like a writer- director-actor. [I’m] not Zach Braff. Actually, what do I know about him? You’re gonna print that and it’s gonna look like I’m an idiot. But Garden State really brought him to a whole other level. If this movie [Hideous Men] does something like that for me, which I’m sure it won’t… I don’t claim to be the next wunderkind.