Almost entirely their own lives.
“Write what you know,” the age-old saying goes. I totally agree. Start with your own life and write as true to it as you can, adding in plenty of details. Even if you’re writing a sci-fi novel, you want the characters’ motivations, dream, disappointments, and conflicts to come from your real life experience. That’s the way it resonates with your readers as authentic and vulnerable.
I just listened to a great “The Daily” podcast on why Taylor Swift is person of the year. Why does she resonate so much with people of all ages? Because her songs come entirely from her very personal, real experiences. She writes her truth. So should you.