Yes, I also noticed such facts.
This is my version.
The body is an anti-fragile thing, up to a certain limit, of course, that is, the more you torment it, the stronger it becomes, and this is not only exercises and contrast baths, etc. these are alcohol and other poisons, but their dosage should be selected individually.
And if the organism is undead, then it will literally start to fall apart, various diseases appear and so on, I have observed it more than once.
In short, it is necessary to torment the body, but not necessarily with alcohol and cigarettes.
I'll start with the second part of the question. She's the most interesting here - and what, excuse me, means "watching your health"? If this means that he listens to the harmful advice of the guru, like drinking 3 liters of water a day, eating fiber like a bison and sitting on a low-calorie diet, or jamming protein shakes and not getting out of the rocking chair - it’s better to do what others do. and psychologically it will be easier to live (and additional stress is also harmful to health), and the harm to health will be clearer and more predictable))) If it is shorter and simpler, people in attempts to become healthier, without understanding the basics of biology, almost always do only worse. Just today I read an article from Toxicology Letters that toxic liver diseases are now becoming more frequent due to the craze for Chinese traditional medicine. So much for your recovery. Apparently, until people start dying in batches from some dietary supplements due to side effects, the Ministry of Health in different countries will not clue in and apply the same requirements to them as to medicines. It's high time.
If you yourself do not know how to do it right, and also cannot distinguish bad advice from good, then it is better not to complicate, and live how you live. Of course, you shouldn't smoke and drink. But then you don't have to bother too much. This is already a lot. It is also useful to walk (in ecologically clean areas) - the safest and most versatile form of physical activity, you don't even need to run. By the way, people who regularly run in the city, where dirty air (and not the fact that there are places in cities where it is clean, even in parks), can harm their health - when you run, you simply speed up your metabolism and absorb from the air more toxins. So much for the benefits of running, yet in any business the head is the most important.
Many adherents of healthy eating look like they are dying. Healthy food has nothing to do with it, it is not worth blaming it, just specific people do not know that their food is unhealthy, but think quite the opposite, and from that, in their obstinacy, they will ignore the prompts of their body that they are doing some kind of game, and will victorious ruin your health)))
And now the first part of the question - "some". Precisely noticed - "some", but the majority greatly shorten their lives. There is often a question of genetics. Someone by nature, from birth, simply "stronger" health. Let's say you have a mutation in a gene that regulates certain processes in your lungs. This mutation gives you a vulnerability to lung disease, so you certainly can't smoke. And someone does not have this mutation, or there is another mutation / gene that even increases the resistance of the lungs to harmful factors. Therefore, all these stories that someone's grandfather smoked from the age of 10 and lived to be 100 - well, what have you to do with it? Even if it was your grandfather, it still doesn't guarantee anything. Until you do a genetic analysis of your DNA, you don't know if you have these longevity genes or not? Do you want to play Russian roulette: smoke and die at 50 from cancer, or smoke and live to 100? It's worth it?
TaAlso, do not forget about additional factors - for example, both drink, but one is from hard drinking to hard drinking and some kind of shmurdyak, and the other is 100 grams of high-quality alcohol 2 times a week. It seems that both drink regularly, but the situations are fundamentally different.
Genetics is also intertwined here on the other hand - smoking and alcohol consumption are addictive, and again, you could be either lucky or unlucky with genetics. What if you are genetically predisposed to addiction and search for novelty. Even if you have a strong liver, you can play the box ahead of time for another reason - for example, you will be poisoned to death by alcohol, because you are a carrier of shitty genes and do not know the measure, or you will be drawn to unnecessary feats under the shaf.