Cassini observations of Saturn provide the most extensive dataset available to characterize the atmosphere of any giant planet. I will celebrate the 20th anniversary of Cassini orbit insertion at Saturn (July 1) by presenting results based on the analysis of observations of the middle and upper atmosphere obtained by the UVIS and CIRS instruments during the last two years of the Cassini mission in 2016-2017. These results provide a snapshot of the middle and upper atmosphere around the northern summer solstice, including a pole-to-pole map of temperatures as well as the distribution of methane and its photochemical products. They provide evidence that the seasonal circulation pattern in the stratosphere penetrates to the thermosphere and allow us, for the first time, infer neutral wind speeds in the upper atmosphere. The retrieved temperatures and winds also demonstrate the importance auroral electrodynamics and heating in controlling both the dynamics and energy balance of the thermosphere. They indicate that polar auroral heating followed by redistribution of energy to lower latitudes (stirring), enabled by momentum deposition by gravity waves and other sources of drag (shaking), is a feasible mechanism to explain the higher than expected temperatures in the thermosphere and therefore to solve the long-standing “energy crisis” on Saturn. Given the similarity of the subsequently observed temperatures on Jupiter, the same mechanism may also explain the temperatures observed in Jupiter’s thermosphere. Finally, we conclude by providing preliminary estimates of what is required to explain the observed temperatures in the upper atmosphere of Uranus, as a first step towards a possible common mechanism to explain the higher than expected upper atmosphere temperatures on the giant planets.