Many write from what they know. Author life experiences can create a myriad of different characters that inspire or antagonize the protagonist in the story. It’s so much like life.
Remembrance of acts of kindness makes a difference in character creation. When I witness people helping people and being generous in times of need, I am inspired. I have watched people with few resources doing what they can for others, giving away more than they can afford. I have felt sadness when there just wasn’t more I could do for someone. Sometimes illness or cruelty was a barrier. Other times, the task was too daunting.
Regardless, the door to perfect interpersonal relationships sometimes shuts for one reason or another. But I still try. A person who attempts to make things better is all I wish for in a protagonist, and it’s all I ask in my life.
As for the antagonist, he/she has shut the door and it may remain locked until I decide it’s okay.
4 Oak Books