Despite his worst fears, Spider-Man: Homecoming star Tom Holland was elated -- an incredibly relieved -- when he finally watched the upcoming franchise reboot.

RELATED: Stan Lee Pops Up in Spider-Man: Homecoming NBA Finals Promo

"I saw it about a month ago," he said last night on Jimmy Kimmel Live, where he appeared alongside Robert Downey Jr. "You know when you revise for an exam and you feel like you crushed it, but the longer you wait for the results, the more you think you ruined it? [...] So walking into the screening, I was like, 'This is gonna be awful, I'm gonna hate it,' and leaving I was over the moon. I loved it."

The 21-year-old actor admitted that he experienced some cultural hurdles when it came to playing the title role of Peter Parker, a high school student from Queens, New York, turned superhero. For starters, in Holland's native England, they don't have homecomings; there, they have proms.

"That was the whole thing," he explained. "We got halfway through shooting the movie and I was like, 'By the way, what's homecoming?' We don't do that. Our proms are very different, though. They serve booze at the prom."

However, that was only for starters, as Holland was unfamiliar with life in an American high school.

RELATED: Spider-Man: Homecoming Finally Has a Chance to Get the Villains Right

"I think that was probably the most daunting part of taking on this character, so as a joke I suggested to Marvel that I should go to a high school undercover," Holland said. "It was completely a joke, and Marvel took it completely seriously. I guess they didn't get my British sarcasm. So the next thing I know, I had a backpack with a pencil case on my way to the Bronx School of Science. I went to school with a fake name and a fake accent.

"And, yeah, the Bronx School of Science is a school for genius kids, and I am no genius," he conti9nued. "Even the teachers didn't know I was not a real student, so they would bring me up to the front of the class and by like, 'What do you think, new kid?' And I'm like, 'I have no idea what you're talking about.' So it was very embarrassing."

A young Peter Parker/Spider-Man (Tom Holland), who made his sensational debut in Captain America: Civil War, begins to navigate his newfound identity as the web-slinging super hero in Spider-Man: Homecoming. Thrilled by his experience with the Avengers, Peter returns home, where he lives with his Aunt May (Marisa Tomei), under the watchful eye of his new mentor Tony Stark (Robert Downey, Jr.). Peter tries to fall back into his normal daily routine – distracted by thoughts of proving himself to be more than just your friendly neighborhood Spider-Man – but when the Vulture (Michael Keaton) emerges as a new villain, everything that Peter holds most important will be threatened.

Arriving in theaters July 7, director Jon Watts' Spider-Man: Homecoming stars Tom Holland, Michael Keaton, Jon Favreau, Zendaya, Donald Glover, Tyne Daly, Marisa Tomei and Robert Downey Jr.