When I understand, I'll let you know.— Mark Hamill (@HamillHimself) August 29, 2018
"Why did Luke give up in The Last Jedi? What other events made Luke give up?" fan Cameron White asked on Twitter, tagging Hamill and writer-director Rian Johnson. "From what we know Luke made one mistake and he gave up. That doesn't really make sense."
"When I understand, I'll let you know," Hamill replied.
The Last Jedi revealed Skywalker exiled himself to out-of-the-way water planet Ahch-To after an encounter with tainted Padawan Ben Solo (Adam Driver) resulted in the destruction of Skywalker's rebuilt Jedi Order. A shamed Skywalker marooned himself on "the most unfindable place in the galaxy," cut himself off from the Force, and waited to die.
"I was shocked. I said to Rian, number one, Luke was the most optimistic, hopeful character, and now he's this miserable, despondent hermit," Hamill said in one interview when asked about his reaction to Johnson's script.
"You see in the story why that is, but I had a real problem, because I don't believe a Jedi would ever give up. You see, if he makes a mistake, he doubles down and does the right thing, regardless of the magnitude of his mistake — choosing Ben Solo and being so wrong and giving rise to the possible Darth Vader."
Hamill famously said he initially "fundamentally disagreed" with Johnson about the direction of the character, but later clarified those comments, saying they were "inartfully [sic] phrased." The longtime Star Wars actor explained he was "surprised" at how Johnson saw Luke, adding it took him "a while to get around to [Johnson's] way of thinking."
Despite a more prominent role than his wordless, movie-ending cameo in The Force Awakens, Hamill conceded Johnson's film was about the new generation instead of his now-grizzled disillusioned Jedi — but to understand Skywalker's fall from grace, Hamill had to invent his own backstory.
"In this new one, I was saying to Rian Johnson: I need to know my backstory," Hamill told The Vancouver Sun. "It was kind of unclear. You read where he is now and what he's doing now and sort of have to fill in the blanks for yourself. So I did do a backstory myself. It's not about Luke anymore, so it's not really important. But I had to make sense of it for myself."
While he "had trouble accepting what [Johnson] saw for Luke," Hamill told IMDb in December he "was wrong" about the then just-released Last Jedi.
Hamill reprises the role in Star Wars: Episode IX under returning director J.J. Abrams. The conclusion of the Skywalker saga opens December 20, 2019.