That’s what we do. Even when we are frustrated or discouraged or feeling very much inadequate … we write.
Even when we don’t feel like it, we write.
Even when we don’t put it down on paper, we write.
A phrase strikes us and we mentally “write” an entire response or description or example or humorous anecdote that connects to that phrase. We see something gorgeous and describe it in our minds. We hear a funny story and imagine which of our characters could tell that story in our book. We read someone’s experience on Facebook, we watch someone in line at the bank or a store, or our neighbor in a restaurant and pick up on details and specifics and things that we could apply in our story to bring it more to life.
It doesn’t even matter if we are currently writing a book, we write these bits and pieces in our minds for future reference.
We can’t help it.
Writers gonna write. That is what we do.
Period.
Patricia Meyers
Paddle Creek Writers 
Yep, I’m at it this morning. Many words to write today!