This paper demonstrates that long-term forward interest rates in the U.S. often react considerably to surprises in macroeconomic data releases and monetary policy announcements. This behavior is in contrast to the prediction of many macroeconomic models, in which the long-run properties of the economy are assumed to be time-invariant and perfectly known by all economic agents: Under those assumptions, the shocks we consider would have only transitory effects on short-term interest rates, and hence would not generate large responses in forward rates. Our empirical findings suggest that private agents adjust their expectations of the long-run inflation rate in response to macroeconomic and monetary policy surprises. We present an alternative model that captures this behavior. Consistent with our hypothesis, forward rates derived from inflation-indexed Treasury debt show little sensitivity to these shocks, indicating that the response of nominal forward rates is mostly driven by inflation compensation. In addition, we find that in the U.K., where the long-run inflation target is known by the private sector, long-term forward rates have demonstrated little excess sensitivity since the Bank of England achieved independence in mid-1997.