We can all get a bit nostalgic at times and yearn for an easier time, a happier time, a time when the sun always shone, or the world seemed a safer place.
We know, of course, that our memory of such times are dependant on our feelings, not our reason, and it has been thus for many a year.
Wishing ourselves back to that gentler time may seem just sentimental nostalgia, and in fact can be dangerous as it can create havoc not just as politics go [think Trump], but also in f.ex. medicine.
In the case of medicine the most important medical decisions are increasingly based NOT on your feelings of how ill or well you are, not even on informed predictions of your doctor, but on the calculations of computers who know you better than you know yourself. Think of DNA tests determining your likelihood of getting f.ex. breast cancer if you carry a particularly dangerous mutation of a gene and what the probability of you developing the cancer is. Even if you do not have cancer the determination may lead you do what Angelina Jolie did to pre-empt the disease.