There's truth and then there's a character's perspective. Both can be honest, even if the reality is experienced in different ways.
I once overheard this conversation:
"I was rear ended in my Dad's SUV last week."
"What happened?"
"An older guy, in his late thirties, didn't stop for the stop sign at the corner . . ."
Funny, isn't it? Obviously the gal speaking was young, in her early twenties, maybe a teen.
The truth is that a man in his thirties is considered young by many, especially everyone over 40. But to that girl, he was old.
When creating a character, set aside your POV and enter hers.
Truthfully, perspective changes as we age. Once you leave your twenties, someone in their late thirties doesn't seem so old anymore.
Writers need to get inside the head of their characters, and they need to adapt the point of view to the character's age, gender, beliefs, location, etc., or the story will fall flat.
Characters must be true to themselves and different from other people in the story. Everything is relative to perspective.
Often a writer needs to research a character to stay true to his/her traits. It pays to put time into fleshing out the folks that populate your book. An incident from a character's past would color their perspective about what's happening in the present.
Need to slip into a character's world and see things through her eyes? A tip I have learned is to go on youtube and watch videos taken where your book is set (if it's a location you're not familiar with). Not only will you see the setting, but you'll hear the way the locals talk and how they refer to things. Clever, isn't it?
Allow yourself to be humble enough to ask other folks their opinion about a situation. Someone else may have an entirely different take on an issue. Their perspective might be just the angle that could add dimension to your character.
See the image above? I love it. I can smell the sharp pine fragrance in the crisp air and feel the warmth of the potbelly stove. But someone with a different perspective would react quite differently to the same setting. Some people might not care for the cold or a private little cabin. Some may find that image upsetting because they would fear a crazy person might be running through the woods looking for his next victim. Whichever view you take is okay, it's just a difference of perspective. :)