Adam Driver found it "terrifying" to act alongside Harrison Ford, Mark Hamill and Carrie Fisher.
Driver - who stars as villain Kylo Ren in the film's new instalment 'Star Wars: The Force Awakens' - also said it was "inspiring" to join the veterans on set.
He explained: "They didn't seem to be people who were like, 'Let me sit you down and tell me what your experience is going to be.' I feel like they're just, even though they obviously were in the original trilogy exhibit to come back to it didn't seem like, maybe a sense of 'been there, done that', so they are not excited about.
"There still was an ambition in trying to get it right and knowing these characters so well and still trying to make it deeper or more resonant. They very much lead by example. That is very inspiring to see, and also terrifying, because no matter how long you get to do this job, you never get to quite figure it out seems, it is both comforting and terrifying."
Meanwhile, the 'Girls' star previously admitted his time with the 'Star Wars' cast was similar to the companionship he experienced in the Marines.
He said: "It's a group of strangers forced to be intimate in a short amount of time. A group of people trying to accomplish a mission greater than themselves. It's not about you. You have to know your role within a team and there's someone who's leading it and, if you're lucky, they know what they're doing."
Tagged in Star Wars Adam Driver