Luke Skywalker was a charming, guileless farmboy when Star Wars fans first met him in 1977. But revelations from "The Last Jedi" have painted him with a darker brush.
Hamill addressed the issue in the winter edition of Disney Rewards Insider, a publication for Disney Visa cardholders.
"In 'Star Wars: The Force Awakens,' Luke has lost confidence in his ability to make good choices," Hamill said. "It haunts him to the core. But he hasn't gone to the dark side. This isn't an evil version of him."
Yet after 40 years of playing Luke, Hamill said he found the character's growth surprising. "It's still an incarnation of the character I never expected," he said. "It has pulled me out of my comfort zone. It's a real challenge."
He also addressed Luke's menacing line, "It's time for the Jedi to end," as heard in film previews.
"This is a huge change for a character who once represented optimism and hope," Hamill admitted. "It's a radical decision to drop out of everything he's ever believed in."
That said, he's not dropping spoilers.
"The entire movie is filled with these kinds of jaw-dropping surprises, but you'll just have to see the film itself to see what they are," he said.
Hat tip to The AV Club for pointing out the Hamill interview. " " opens Dec. 15.