There’s one line in particular in A New Hope that can be blamed for this — Hamill certainly does. This is the Star Wars scene that did it.
Hamill explained the teenaged-sounding line from the start of the movie; “But I was going into Tosche Station to pick up some power converters,” to Entertainment Weekly, stating, “I’m going to have to make this as juvenile as I can so there’s room for growth. And I sort of wanted to make it sound like I had four sisters and two brothers when you’d be in the car and they’d say things like, ‘You said we could go to the mall.’ So I wanted to give that flavour.”
“It was cringe-inducing even at the time,” he says. “But I explained to George [Lucas] what I just said to you, and he said, ‘Yeah, okay, do it.’ Little did I know that it would haunt me for decades.”
Perhaps one of the best things about Luke is that he’s not a flawless character, as cemented in the rather divisive The Last Jedi, so we understand, Mark.