Luca's titular character was originally scared to be human. Pixar’s latest animation, directed by Enrico Casarosa, is set in the seaside town of Portorosso and follows Luca, a sea creature who can change into a human, as he journeys from the water's depths to land. Life as a sea monster has never been so fascinating and, while Luca and his friend Alberto are capable of changing their scaly, colorful exteriors, Luca isn’t so keen about transforming into a human at first.
Luca begins with its titular character in his natural habitat: the sea, where he lives with his parents and grandmother. Luca herds fish everyday, but doesn’t have much of a social life beyond that. By comparison to Alberto — who is always hanging out on land and was forced into independence after being abandoned by his father — Luca has lived a very sheltered life. His mother, Daniela, is always worried about him going to the surface and doesn’t encourage it because she knows how terrified humans are of sea monsters. Luca’s fear of being human largely stems from his mother’s own overprotectiveness. Daniela instilled a lot of caution in her son with regards to being topside and so his hesitance is partially an extension of hers.
Fear is a learned behavior and the idea of being a human was not only strange, but potentially hazardous to Luca’s well-being (at least from his parents’ perspective). After all, Daniela knew that curiosity would not only lead Luca to the surface, but put him in close proximity to humans, leaving Luca vulnerable. There’s also the fact that Luca had never transformed into a human before he met Alberto and he had no previous notion that he could even become one. Floating to the surface may sound exciting and adventurous, but watching as his skin physically changed from sea creature to human was probably an overwhelming and strange experience for Luca. It’s why he was so quick to return to the sea immediately after seeing his new look for the first time — he knew he would be safe and comfortable there because it was his home.
Alberto, on the other hand, was already used to being on land and so the novelty of it all had probably worn off for him. For Luca, the ability to become a human was never on his radar at all and he’d stayed away from swimming to the top all his life. It’s only natural that he had such a visceral reaction to his human transformation. His experience of changing from sea monster to human can be likened to a baby seeing themselves in the mirror for the first time. The surprise of being human was intense at first, but Luca got used to it after a while and actually grew to love it quite a bit.
Luca pushes through the intensity of the character's shock and fear of being human to showcase the rewarding feeling of doing something despite the trepidation that may have come beforehand. Luca had a few reasons to be afraid of something he had never done. Being a human meant venturing into unknown territory for Luca, much of which was driven by how much he didn't previously understand about the world above and the sheltered way he grew up. Luckily, he was able to overcome his hesitation to discover something pretty amazing.