The true saddest scene is "I've got a dream". Most people see it as a happy song, saying that people aren't always as they seem, and it's true; in a way. But what makes it depressing, is that people disregard Flynn's dreams. The saying "Your dreams stinks" is heart breaking. While else is singing about puppet shows and pianos, he's talking about improving and moving up from his sucky childhood.
From the "I have a dream" and the Campfire scene after, you can see that Flynn grew up in a poor orphanage. I'll break it down for ya, so you don't have to do the research.
Some where warm and sunny: Research says Tangled most likely happened in Germany around 1840s. Winter in Germany gets to -10(C) degrees (5)(F). A poor orphanage wouldn't have enough blankets to keep everyone warm. He wants a place where he would never feel cold again.
On an Island that I own/ For a kid that has nothing: He wants an Island, because it's something few own, and it's his. He most likely had to share everything with the other kids. So, he wants something to cherish, that's only his.
Rested and alone: With a whole bunch of traumatized kids together he probably got little rest; and defiantly little alone time. He's tired of being surrounded by people, who just won't leave him alone.
Surrounded by enormous amount of money: Depending on how poor the orphanage was, they probably worried how they'd pay for housing, food, and clothes.
He's the one that read to the rest of the kids. Most likely he's the oldest; he watched out for the other kids.
He even went as far as to change his name. Eugene is the poor kid with the weight of the world on his shoulders. Flynn is the care fee, role model who is successful and safe.
So while everyone else wishes for something they want. He wishes for something he's earned for since he was a kid. He wants a stable, safe place, where he doesn't have to worry. And the other people just threw it away. This is why I've got a dream is the saddest part of Tangled
It also speaks of how much Repunzel means to him. That he's willing to throw away the dream he's had for years, for her. She must mean a lot to him.
Although he's not perfect, he did leave the brothers, he's more thought out then what most people see him as.