In the real finding Nemo story, it's all about a father's love for his son. Marlin, the clownfish father, is overprotective of Nemo because Nemo's mother was killed by a barracuda when Nemo was just an egg. So when Nemo is taken away, Marlin is desperate to get him back. He travels through the vast and dangerous ocean, which is full of predators and other obstacles. Dory, his new friend, adds some comical and also helpful elements to the story. Their journey is filled with excitement, like when they have to escape from sharks and jellyfish. And in the end, Marlin's determination pays off as he is reunited with Nemo.
I don't really know the significance without more information. It could be significant to the people directly involved in the story, like if it's a family's story, it might be important for family heritage.
I'm not sure specifically which 'nemo sad story' you're referring to. It could be about a fish named Nemo having some sort of misfortune like getting lost, separated from his family, or facing danger in the ocean.
Finding Nemo is purely fictional. The characters and their adventures are made up to entertain and charm audiences, rather than being drawn from real-life events.
The story begins when Nemo is taken away from the ocean. Marlin, overcome with fear and worry, sets out on a dangerous adventure to rescue him. Along the way, he meets various characters and faces numerous challenges.