This rule can only work in one case - a person has very good genes.
The rest is a myth, health should be monitored, especially for people with congenital diseases. Careful monitoring of well-being is the key to a high-quality and long life.
I think that, in fact, there is no such trend. There are simply times when someone cares and dies before someone who does not care. Such cases are striking. But this is not a trend. Indeed, there are those who by nature have a more powerful organism, and these people sometimes do not have a special need to monitor their health, while others, on the contrary, are prone to diseases and have to be attentive. It would have been even worse if they hadn't followed.
Most likely your "statistics" are spoiled by those who have simply faced health problems and faced so seriously that they began to monitor their health especially noticeably.
This is understandable and normal. In order for a person to understand how you get the flu, what complications can be, he needs to feel it. If a person gets sick over and over again and does not notice anything, then he thinks that nothing terrible is happening and cannot happen. Why then care and monitor?
Scientists say that 10% of people do not get a noticeable flu at all. Such genes. Why would they care about getting the flu? And each influenza suffered little by little shortens life with its poisoning of the body - complications.
Someone, by virtue of the lifestyle of their parents, for example, not caring, has learned to do something right. He doesn't care either.
Someone, for example, is asthmatic. You will notice how he takes care of his health, for him it is already a matter of life and death. And, of course, he will die before others, simply because he is a chronically ill person.
I know people whose parents and they themselves have never had and do not have dental problems. Of course, from the outside it will look like they don't take care of their teeth, but everything is fine. But this is a question of heredity. And genes, and living conditions of parents.
It's like with alcohol. Someone from 100g is bad, and someone will drink 500g and nothing. And the reasons can be very different. The one to whom nothing, perhaps, is already an alcoholic, and you just do not know it. At a certain stage of alcoholism, the dose of drunkenness increases markedly. Or maybe his health is just excellent, he has a good snack, maybe he poured half of it somewhere, but you think he drank. And you, perhaps, simply genetically determined intolerance to ethanol. Or some kind of chronic illness, or you don't follow the daily routine and your body is in bad shape.
There are too many factors to draw conclusions)