Naturally, Optimus Prime voice star Peter Cullen is thrilled that "Transformers: Revenge of the Fallen" is finally rolling out into theaters. But while the live-action transformation of the robots in disguise has been the toast of Hollywood for the last couple of years, Cullen is not about ready to forget where it all began with the animated series 25 years ago -- and the fans who helped make it a classic.

"What really impresses me with BotCon and other conventions, and shaking hands with people, signing autographs and talking with them, is the amount of people in their 30s who still hold on to a genuine sense of appreciation for the original animated shows," Cullen said in an @ The Movies interview Tuesday. "They're guys and girls from all walks of life. It gives me a great feeling of satisfaction to know that I was involved with something that could have such of an endearing quality."

Inspired by the Hasbro action figures released in 1984, the characters in the Transformers universe soon appeared in comic book form and in their own animated TV series. In addition to the show, Cullen voiced Optimus Prime for the animated feature film in 1986 and 21 years later, he was summoned by director Michael Bay to voice the iconic character for the first "Transformers" live-action film. This week, Cullen reprises the role in Paramount/DreamWorks' "Revenge of the Fallen" on the heels of last week's release of "The Transformers: The Complete First Season" on DVD (Shout! Factory).

Cullen, 64, is certainly no stranger to the voice acting business, and for more than three decades has recorded roles for such classic animated series as "G.I. Joe," "Voltron," "Alvin and the Chipmunks" and "Winnie the Pooh" (as the lovable donkey Eeyore). But it's his role as Optimus Prime that's had perhaps the biggest impact on fans.

How Cullen came up with the voice of the character is a unique story within itself. Quashing the rumors that it was inspired by John Wayne, Cullen said his vocal delivery for Optimus Prime is essentially an impersonation of his older brother, Larry, a veteran of the Marine Corps. Cullen said Larry, who is 13 months his senior, "saw a lot of action and a lot of tragedy" as a grunt in Vietnam, and received the Bronze Star and the Purple Heart for being wounded during his time of duty.

While sharing an apartment with Larry in Los Angeles in the early 1980s, Cullen said a conversation with brother prior to his audition for Optimus Prime serendipitously provided him with right tone for the character.

"Not knowing what I was getting involved with, I remember being exuberant while we were sharing a cup of coffee and being more expressive than usual," Cullen recalled. "Then, he said to me in his relatively deep voice, 'Peter, don't go over overboard with your audition. Just cool it. Be in control. Just be calm and go get 'em.'"

"So when I got to reading the breakdown of Optimus Prime, I could see what they were going for -- dignity, honor and coolness, and the empathy and leadership at the time. He had tremendous character and Larry's voice came to my mind," Cullen added. "He had this controlled, Marine Corps leadership voice. So it just hit me and I came out with an impression of Larry's voice -- I was just lucky enough to be with him that morning, to be able to incorporate his sound and knowing who he was as a person." Using his brother's voice as a springboard, Cullen said that he immediately embraced Optimus Prime not as merely a robot, but a heroic character with several dimensions.

"There was a direction by the author of the character to bring forth truth and dignity. Character counts," Cullen observed. "Unlike the many of the heroes in my youth who were just about good versus evil and breaking up the bad guys to win, there was something more to this. There was compassion and understanding. I highlighted those qualities."

While Cullen is primed to voice Optimus again, he'll be anxiously awaiting what the future holds for the character after the new movie. In the realm of the Transformers universe, the character has been killed off before, but thankfully brought back to life. And in "Revenge of the Fallen," we come to discover that Optimus Prime is vulnerable once again.

"I don't know where things are going from here … hopefully Optimus Prime and his iconic moments of integrity, honor, courage and nobility will remain," Cullen said. "But who knows, to see what's transpired from 1984 to seeing the movie at the premiere, 'Transformers' has come a long, long way."

No matter the case, there will always be inspiring reminders of the roles that surround Cullen, whether it be through the films, TV shows or Transformer toys, which also feature the actor's voice.

"There's a warm glow that often accompanies the discovery of a toy or when you're walking by a window somewhere and you see a picture of Optimus," Cullen said, humbly. "It makes you feel all at one with your life and what you've done. No matter what the differences are -- whether there are people who are getting 1,000 times the amount that you're getting -- from what I'm getting in terms of satisfaction and pride, there's no alternative to that."