Perhaps you've heard this story. There was a dad on a crowded bus with his children-maybe three of them, I don't remember exactly-and they were misbehaving. Enough so that a woman turned to him and asked him to control them. His glazed eyes focused on the woman, and he apologized for their behavior, saying that his wife, their mother, had just passed away that morning.
If that isn't enough to make anyone feel like a heel, I'm not sure what is. Any situation can be turned upside down by simply coming at it from a different perspective. Maybe another woman on the bus was silently crying because her child has cancer and can't play, or a grandmother who was inwardly cheering the kids on because she knows those years don't last forever, and to squelch them at such a young age could make them grouchy adults.
You just never know.
And that's one thing that makes writing both exhilarating and challenging. In order to write a great story, each character needs their own goal and motivations. Sometimes they may align, but things get infinitely more interesting when characters have a different perspective on a matter.
One of my favorite examples of this is Magneto and Professor X of the X-Men comics. They live in a world where mutants are popping up everywhere, and each of them has a very different perspective on how the people of the world will treat them.
I stole this off of wikia in their villains section.
Despite once being close friends with Professor Xavier, the two became enemies when Xavier championed the co-existence of mutant and human kind working together. To Magento, a Holocaust survivor who had seen and felt first-hand the worst ways human beings could treat those they deemed different, such a system was impossible and he instead championed a violent pro-mutant stance, one which saw humans as the enemy in a genetic war and promoted the idea that mutants should become the dominant species on Earth.
Later in the entry, it states that Magneto's goal is protect mutantkind.
The character lived through the Holocaust. Of course he's not going to easily believe that humankind will simply accept mutants. They're different, which means they will be hated.
Professor Xavier didn't have a traumatic childhood. He went to college at Oxford, for crying out loud. Naturally, his perspective is going to be different than Magneto's. This is what wikia hero says.
Professor Xavier's ultimate goal is a world were all people are equal regardless of their origin...
Each character fights for their cause. Sometimes they align in their goals, other times they are directly fighting with one another. Is either character tragically wrong? The comics show us again and again that no, they're both right. And they're both wrong. That's what makes the conflict so interesting.
Can you think of any other good examples of this?