Writer's Opinion

What doyou think of someone who writing about something that has neverhappened to them?

Because their alot (I mean alot) of books that are published with authors puting a character though something. That has not happened to them in real life.Yes, I admit that I write about things that have never happened to me. But also their is a saying thatsays "A writer writes about what they know."

Please give me an honest opinion.