Is 'write what you know' simply misunderstood advice?

Can I still write about witches and magic??

Here’s what needs to be made clear when talking about ‘write what you know’: No one is saying you have to actually be a murderer to write a book from the point of view of a murderer!

Apparently Mark Twain is the culprit of the ‘write what you know’ advice (Mark Twain, what a monster you’ve created!).

Since I’ve been aware of write what you know, I’ve mostly heard writers pooh-poohing the idea and telling newbie writers to completely ignore it. But I think it’s simply misunderstood advice.

Now perhaps you’ve heard all this before, but if so, stick with me because I’m going to use examples from my own life and how I’ve infused my personal experiences into my writing to better connect with readers.

… the first field of the writer’s enquiry actually is the writer. Find out who you are and what you know, and then more or less forget it – fly off wide of your own base.

Dear Writer Revisited, Carmel Bird