Hollywood came out in full force over the weekend to attend the world premiere of Star Wars: The Last Jedi—but Carrie Fisher, one of the series’ brightest stars, was noticeably absent. The actress, who died in December 2016, reprises her role as General Leia Organa in the film, 40 years after she played the princess from Alderaan in 1977’s Star Wars: Episode IV: A New Hope.

Mark Hamill, who returns as Leia’s long-lost brother, Luke Skywalker, shared his memories of Fisher in an exclusive interview with E! News. “She’s wonderful in the movie,” he said. “I always think of her in the present tense, not the past. If she were here now, she’d be giving you the bunny ears, flipping me the middle finger. I mean, she was just fun to be around—all the time!”

Hamill honored her spirit by staying positive. “Instead of being upset that she’s not here, I have to remember all the years of fun that she gave me,” he explained. “I met her when she was 19!”

Harrison Ford‘s Han Solo was killed in 2015’s Star Wars: The Force Awakens, meaning Hamill, 66, is the sole veteran among newcomers John Boyega, Oscar Isaac and Daisy Ridley. For this movie alone, the actor has traveled to Mexico City, New York City and Tokyo—and he’ll soon appear in London, where Prince William (who makes a cameo as a stormtrooper) will join him.

Needless to say, the travel schedule has taken a toll on the cast.

“You’re falling asleep at 1:00 in the afternoon and waking up at 4 a.m., so it’s been tough,” Hamill admitted. “But I love it.” And he was bound and determined to stay alert during the premiere. “I think the Dolby sound, or whatever it is, will keep me awake—although, my son is the king of falling asleep in blockbuster movies,” he joked. “I hope he can stay awake tonight!”

For more Star Wars stories from Hamill, watch the video above now.

Star Wars: The Last Jedi is in theaters Friday.