When “Finding Nemo” was released in 2003, Hayden Rolence wouldn’t yet be born for about two years, so his parents never could have imagined their little boy would end up reprising the voice of Nemo in that hit movie’s sequel, “Finding Dory” (opening Friday).

The Aurora youngster —  who will enter seventh grade this fall — sat down earlier this week to share his tale of coming to be the voice of one of the most beloved animated characters on the planet.

“I know it sounds pretty simple, but basically, my agent sent a tape of me to the producers,” said Rolence. Prior to that, the pre-teen had received a sample script “that I read over and over and over again.”

That came after the young man watched and, more important, closely listened to “Finding Nemo,” so he could “come as close as I could” to the inflection and voice nuances of Alexander Gould, the original voice of Nemo. “I knew they would want people to watch the new movie and not be distracted, thinking the voice of Nemo had somehow strangely changed,” said Rolence.

Asked what he thought when he first learned he had been cast to voice Nemo in “Finding Dory,” the young actor laughed. “I was in disbelief. I said, ‘You guys are joking with me, right?’ ”

As for watching the original film as much as he had, Rolence noted that if pushed, “I could probably recite the lines from ‘Finding Nemo’ pretty much from memory.”

His road to acting started very young. “Actually I started modeling and doing some of that kind of stuff when I was 5. When I was 7, my agent called my parents and asked, ‘Does Hayden act?’ and they said, ‘Um … yes!’ ” —  noting that the youngster was quite the performer at home.

The process of going to California and working with the Pixar team to make “Finding Dory” has been a wonderful learning experience for Rolence and his family. Asked what he had learned, the boy said, “I learned that it takes a lot of time. It takes a lot of ideas. And it takes a lot of people who do a lot of hard work.”

Speaking of hard work, Rolence admitted the actual voice recording wasn’t easy. “There is so much repetition. For example, I had to repeat the word ‘dad’ like 400 times — giving it all kinds of different interpretations, depending on what the director wanted.”

Hayden Rolence (left) and Alexander Gould, the original voice of Nemo. |Jesse Grant/Getty Images

Hayden Rolence (left) and Alexander Gould, the original voice of Nemo. | Jesse Grant/Getty Images

Beyond that, Rolence explained that, as is usually the case on animated movies, “You’re pretty much alone in a [sound] booth with only the director talking to you. You have to act like you’re talking to other people, but you’re not talking to anybody.”

As for co-stars Ellen DeGeneres and Albert Brooks, Rolence said he did meet them during the filmmaking process, but only because he ran into them before or after his own recording sessions — in a hallway at Pixar. “But it was really cool to meet Ellen. She’s really, really nice and funny,” said the suburban native, who previously had only seen DeGeneres on her daily TV talk show.

Outside of acting, Rolence sounds like a lot of kids his age. Asked what he likes to study in school or do outside the classroom, he said, “I love science and math. I like reading. I like playing golf and swimming. … Pretty much I like doing regular kid things.”

One not-so-regular “kid thing” Rolence will be doing Friday will be joining his parents and a large group of family members and friends as they rent out an entire local movie theater to watch “Finding Dory” on the day it’s released nationwide. “We’ve invited a lot of people and we will just be having fun,” added the young actor.

He then turned quite serious as he shared some advice he would give to another youngster who might want to follow in Rolence’s footsteps and become an actor.

“I would advise them to make every little bit of acting fun. That’s because you will have to sacrifice a lot of time — both your time and your parents’ time,” said Rolence, as his mother slowly nodded knowingly, sitting nearby.

“Yes, you have to sacrifice a lot of time to be able to do acting. So make every little bit fun, because it will be hard and there will be lots of long, long days — trust me!”