How do we recreate the real world in fiction?

Recreating ancient history can be fraught with interpretations. But recent history must surely be just as hard. They tell us we should "write what we know" but I'm always afraid what I know might be skewed by what I thought I knew. If I painted the world I grew up in, I know my brothers would disagree. My older brother has already complained about things I said as a young adult that I can't even imagine wanting to say. There again, in fiction, the world is seen through a character's eyes. So...