Voice of Nemo from Finding Nemo reflects on how much the movie changed his life 20 years on

As Finding Nemo turns 20-years-old this year, the voice behind Nemo has reflected on his most famous role.

Alexander Gould was just nine-years-old when he voiced the little fish, who ends up getting abducted and placed into a dentist's fish tank in 42 Wallaby Way, Sydney.

Now, say that address five times fast.

A pretty big achievement indeed.

Reflecting on the movie's lasting legacy, Gould, now 29, said to ABC that the film has 'so many beautiful themes'.

"I think that's probably why it was such a cultural phenomenon at the time. It just spoke so deeply to everybody who watched it." he said.

"You pick up all the good messages of having faith in yourself, trusting yourself, being able to overcome obstacles in your own life. Things that might seemingly hold you back don't actually hold you back.

For Gould, the film was a pretty lengthy process, a whole 'three years of recording', as he started on the role when he was six years old.

He said that he was often 'going back and forth to Pixar in San Francisco and going to Disney in Los Angeles'.

"And finally, after many, many months and years of collaborating and working on the film, it kind of all came to fruition and then there was a lot of big media attention, and there was premiere and it was very fun." he added.

"I kind of was in the Disney crowd at the time, which was exciting. It was a really fun time."

"I remember Ellen was hilarious and very fun and treated me very well. Albert was really sweet and kind. I actually ended up working with Albert a lot more on "Weeds." Gould said.

"He played my grandfather for like a whole season, so I got to actually develop a bit of a relationship with him. He's a really, really sweet guy."

Despite having a 'fun time' on the film, Gould did not return to the cast back in 2016 when Finding Dory hit cinemas.

It was said that the actor didn't return to the role as he no longer had the voice when he became a teenager, which he confirmed.

"After the filming of Finding Nemo I still did the voice ... until I was about 14. Around that time I was told that, unfortunately, my voice had changed too much. I wasn't able to capture the essence of Nemo anymore.

"That happens when you're a child actor. So they brought in someone new [Hayden Rolence] who was able to capture the essence that I had in the original film, and he did a really fantastic job doing that." he said.

However, he added that he did come back to the sequel for a 'small little cameo'.