r/MachineLearning - [D] Misunderstood ML/AI Concepts

What are some concepts which many people who use Machine Learning / Artificial Intelligence get "wrong" or misunderstand? What are some good articles (research and "lay") on the subject? What might be some good or interesting "polling" questions to tease these sorts of things out? Note: I would love and/or encourage anyone to take the result of this discussion and turn it into a peer-reviewed-caliber paper. I've been thinking about it, but realistically, I probably won't do it, so knock yourself out!