The concept of nostalgia has an invaluable advantage: In contrast to other cultural concepts, it has an exact date of birth. It was in 1688 when the medic Johannes Hofer published a thesis in which he described an illness he termed with the neologism “nostalgia.” But instead of following the academic and larger cultural discourses that evolved from this starting point until the present, the question that deserves some attention is which temporal setting goes along with the concept of nostalgia. Most of the experts on nostalgia as a sickness during the last three and a half centuries did not diagnose themselves but others, quite often patients from rural areas who had to leave home to work abroad, where they became nostalgic. With this diagnosis these experts also established a certain time-model, because they separated a “modern” time-model of irreversibility from a “nostalgic” time-model of reversibility. If we take a closer look at the nostalgia diagnosis and its consequences, we might also gain some ideas for our thinking about the theory of history.