That, along with his haunting performances in films like Never Let Me Go and Boy A, would be enough to justify the It Boy buzz that now swarms around him—in his mind, apparently, like a cloud of gnats. Tell him he's in an enviable place and he grimaces. "I'm going to ignore everything you just said," he says with a wary dip of the chin. "Because it doesn't mean anything." He resists talking about his girlfriend, actress Shannon Woodward, and he's openly disdainful of the Young Hollywood party circuit. "Those events that look like so much fun in the photos you see—it's mostly people looking over their shoulders at everyone," he says. "They're miserable, those parties."

Okay, but isn't he ever tempted to ring up, say, The Bazaar by José Andrés and make a midnight reservation for "Spider-Man, party of 27"? "I wouldn't be able to live with myself if I had done anything so crass and obscene as that," he says. "No fucking way. I would literally be sick on myself throughout the dinner."

Nevertheless, when an international entertainment conglomerate decides to "reboot" a superhero franchise and heap upon your skinny shoulders the burden of producing billions of dollars in potential revenue, brushing off the outsize expectations (and the prying media) is no longer an option. "I see it as a massive challenge in many ways," Garfield says. "To make it authentic. To make the character live and breathe in a new way. The audience already has a relationship with many different incarnations of the character. I do, as well. I'm probably going to be the guy in the movie theater shouting abuse at myself. But I have to let that go. No turning back. And I wouldn't want to."

Not to fry his nerves even more, but it's worth pointing out that for every actor who has expertly squeezed his cool indie sensibility into a spandex unitard—Christian Bale, say, or Garfield's own arachnid predecessor, Tobey Maguire—there's another newly hatched superhero who's been foiled again. Ask Brandon Routh. Or Eric Bana. Or Ben Affleck. It would've been safer for Garfield to take the Ryan Gosling and Joseph Gordon-Levitt route: Just keep plugging away at the arty prestige flicks until adoring critics drag you into the glare.

But he's right. He can't turn back. By now, all the physical training for Spider-Man (including a lot of yoga and pilates) has transformed his physique. "I want to feel stronger than I've ever felt, and I want to feel more flexible than I've ever felt," he says. "I want to feel powerful. You don't just want to be a pack of meat—it has to be an open body. It does something to your psyche, and it does something to the way you move." As far as the psyche is concerned, anxiety about whether he's man enough for the job is part of the Peter Parker gestalt. "Whenever I have a moment of doubt, I'm very easily able to equate it with the character struggle I'm stepping into," Garfield says. "And that's immediately reassuring—it feels like I'm in the right place for this."

He already has a sense of how the wrong place would feel: Thanks to a misunderstanding, Garfield was convinced that after endless hours of screen-testing for Marc Webb, the (500) Days of Summer director who has signed on to make the new Spider-Man, he'd once again managed to bungle an audition. Garfield and a few Social Network castmates, including Justin Timberlake and Jesse Eisenberg, had flown down to Cancún to promote a slate of Sony movies. The air hummed with anticipation; Sony was supposed to make a Spider-Man announcement soon. Garfield was already racked with uncertainty. "I was genuinely expecting 'You're just a shit actor' instead of 'We want you to do it.' "

Amy Pascal, cochair of Sony Pictures, invited the Social Network posse to a private dinner on the beach. "I was reading her like she had the answers to the universe," Garfield says. Someone at the table asked, "So, Amy, what's going on with the new Spider-Man?" Garfield tensed up, fighting the urge to flee. He and Timberlake shot each other glances across the table. Pascal slowly spun toward the questioner—turning her back to Garfield—and proceeded to deflect the query. "No news at all."

The impromptu inquisition went on and on as Mr. Oblivious kept needling away with questions like "Wasn't there anybody you guys liked?" It got painful. "Andrew assumed my silence meant that he didn't get it," Pascal says. "I practically broke into tears. This poor kid—who is Spider-Man—was going to be in for a terrible 24 hours." Garfield pinched her leg under the table—"not in, like, a weird way," he says. "I was just trying to make her giggle and let her know that it's absolutely fine." Even if it wasn't.