So let's say in the population, you had the point, so one instantiation of the random variables, you have, you sample once, I guess, from the universe. And you get x is equal to 1, and that y is equal to, let's say y is equal to 3. And let's say that you knew ahead of time that the expected value of x is 0, and let's say that the expected value of y is equal to 4. So in this situation, what just happened? Now we don't know the entire covariance, we only have one sample here of this random variable. But what just happened here? We have 1 minus, so we're not going to calculate the entire expected value, I just want to calculate what happens when we do what's inside the expected value.