And it depends how you think about the word average. Because we are squaring the residuals. So outliers, things that are really far from the line, when you square it, are going to have disproportionate impact here. If you didn't want to have that behavior, we could have done something like find the mean of the absolute residuals. That actually in some ways would have been a simpler one. But this is a standard way of people trying to figure out how much a model disagrees with the actual data. And so you can imagine, the lower this number is, the better the fit of the model.