I can barely contain my joy about being in perfect health.

Clean sheets. A hot shower. The first mouthful of something cold when you are properly thirsty. Whatever your body is currently doing, it can still deliver these, and it delivers them at full strength.

Joy about a body does not scale with how well that body is working. It arrives in the same size units either way — thirty seconds at a time, physical, requiring no good report from anybody. Someone in a hospital bed with clean sheets and a window is getting the same delivery as an athlete.