I love this. Most of us only know the areas where we have lived or been surrounded by. For an Army brat they are constantly being moved around the country and sometimes even living in different countries. For another they may have lived in the same small town their entire life. Another might have been raised in the foster care system constantly being moved from one home to another.
Think about it. We are all so different. No two people have lived the exact same life. Yes, many people have lived similar stories but they are not the same.
The same thing is true when it comes to writing. You can have two stories with similar characters but the stories themselves are so very different. And that is good. Would we really want cookie-cutter stories? Absolutely not. We’d read one and then get bored with all the rest. We need them to all be different to keep the reader’s interest.
So we ultimately write what we know and have observed. We write about our own little corner of the world as we know it.