Being Spider-Man is never easy, but it was especially hectic in the days before Tuesday’s opening of “The Amazing Spider-Man.” In a weeklong New York publicity blitz, the film’s cast and crew visited schoolkids, planted community gardens and sounded the New York Stock Exchange’s closing bell. One warm Wednesday, a stunt man dressed as Spidey rappelled down the side of the American Museum of Natural History, hand-delivering a Chilean Rose tarantula for an upcoming spider exhibition. Andrew Garfield, the movie’s star, joined the ceremony at ground level.

“It’s the mask that means everything,” Garfield says. “That’s what kids are excited to see. You know, I walk into a room and there’s a bunch of kids, and they’re like” — he shrugs — “ ‘whatever.’ Their parents will be, ‘That’s Spider-Man!,’ and they’re, ‘No it’s not. It’s some white dude with big hair.’

“And I’m, like, ‘You’re not wrong.’ ”

Tucked into a private room in the museum after the tarantula delivery, the 28-year-old seems to be feeling the long, global promotional campaign. Garfield has been in well- publicized films before (his last two were “Never Let Me Go” and “The Social Network”), but things are different with a cinematic series whose long-term earning potential equals that of a small industry.

“I question this whole process of selling a movie so intensely,” he says, with little prompting. “It does something to you, to your brain. It’s felt like a lifetime of repeating yourself.” In this context, even an admission of lifelong love for the Spider-Man character — a love shared my millions — risks sounding scripted. Speaking of the hazards of taking over a role strongly associated with another actor — Tobey Maguire’s hugely successful three-film tenure began only 10 years ago — Garfield says he worked to focus on the thrill of the job, “just like Peter Parker has to attempt to hold onto the joy of being Spider-Man as he goes through trials and tribulations.”

When word got out that Columbia intended to start from scratch after 2007’s “Spider-Man 3” — what’s known in the fanboy world as a “reboot,” reimagining the hero’s origins and persona — many observers felt it was much too soon. Why remake something that, at least in its first two installments, had so successfully delivered superhero thrills?

“I get it,” Garfield acknowledges. “I understand that perspective. But it’s not my perspective.” He claims that “before I even dreamed that I might be a part of it, I was really excited” at the prospect of seeing someone else offer a new take on a character who, in the comics, has gone through many more incarnations than he has on screen.

It’s plausible that Garfield wouldn’t have assumed he had a shot at the part. Although born in America, he was raised in England and speaks with an English accent. He has convincingly played an American before (in Robert Redford’s “Lions for Lambs”) and was praised for his performance in “The Social Network,” but he was already 26 (albeit a very young-looking 26) when he auditioned to play 17-year-old Peter Parker. If Sony, Columbia’s parent company, had waited much longer to relaunch the series, Garfield surely wouldn’t have been in the running.

So maybe it was lucky that the third Tobey Maguire/Sam Raimi “Spider-Man” film left an aftertaste many were eager to erase. Accustomed to the stay-positive protocol of PR campaigns, Garfield’s interviewer is shy when admitting how disappointed he was in that movie — only to have the actor unexpectedly interrupt with “I was too.”

Is the new face of one of Hollywood’s most profitable franchises really allowed to criticize its last installment? “I’m my own man,” Garfield says with a laugh, although he hastens to add that, as someone infatuated with the comic book’s long history, he could identify with the filmmakers’ urge to cram in more elements than could possibly fit in one coherent movie. “It was stupid. But it was awesome.”

So, is there already a three-movie storyline mapped out for this new Spider-Man? The actor chuckles: Even this first chapter wasn’t completely plotted when he started work, he says.

“Um, it was, it evolved every day. Yeah, it evolved, we’ll just say that.” Having a fluid script might have made for a scary work environment, but it also seems to have afforded the young star more input than he expected.

Having first encountered Spidey in the old animated TV series, with its bright colors and infectious theme song, the actor appreciated Maguire’s wide-eyed, all-American take on the character. But once he got the role, he was eager to bring a less candy-coated sensibility to it.

“Obviously, I didn’t decide the tone of the movie,” he acknowledges.

But in preparing for the role, he pondered what being orphaned meant to the youth — he agrees that this Peter comes across as somewhat troubled, psychologically — and worked to bring the character into the present day. Being a nerd has changed, after all, since Peter Parker was created in 1962.

Before he acquires superhuman powers, Garfield’s Parker is skittish and reticent. He hesitates before speaking, as if reluctant to commit thoughts to speech. He’s less an outcast than a loner; he travels by skateboard.

“It was my idea that he skateboarded,” the actor says, proud to have introduced a story element that not only brings new sociological associations to the character but offers a new angle on his physicality. If Maguire’s Peter Parker resembled the scrawny kid in a Charles Atlas ad, awestruck when a radioactive spider’s bite makes him muscular overnight, Garfield’s has a more hard-wired sense of movement and speed.

When it came time for the filmmakers and CGI animators to envision how this Spider-Man would move through the air, Garfield insisted on being involved, using acting-school techniques of animal imitation to imagine how a human kid would adapt to his new powers.

“I was panicked throughout the process,” he recalls, stuttering and gesticulating as he describes his concern about meshing his own performance in the red-and-blue suit with shots of a computer-generated web slinger swinging past skyscrapers. “ ‘Are we going to be in two different movies? We have to be in the same movie,’ ” he remembers worrying, knowing that whatever the CGI Spidey did was “all representative of Peter and therefore representative of me.”

In the end, the illusion is convincing. Thanks both to improved effects work and a distinctive movement style, it’s harder to watch Spidey in this film without imagining the human kid underneath the mask. Even very young viewers may find the connection hard to resist.

Maybe, just maybe, when the time comes to do a promo tour for the sequel, kids will be as excited to see Garfield as they are to watch the costume-clad stuntman next door.

DeFore is a freelance writer.