Very well said, Michael. It also frequently operates on a personal basis for the speaker, i.e. “I’m this way so my way must be the best.”
The ‘Exercise’ thread makes me think of that - in no way is it necessary for everybody, to lose weight on a ketogenice diet (and this is generalizing that they need keto and have a background of metabolic disturbance from eating a lot of carbohydrates).
Yet it still makes a massive difference for many people.
Eating the chocolate bar every day - I could see this; I think it’s a case of, “Well, if it didn’t do any harm then it didn’t do any harm.”
You hear it about cigarettes/tobacco, “Lived to 90, and smoked 2 packs of cigarettes every day right to the end.” – Well, maybe so, but I bet that if one was really familiar with the person in question, there would be some observable detriment from all the smoking.
“Drank a fifth of liquor every day…” I know a lot of people like this, a consequence of where I’ve lived and worked. I would go so far as to say they don’t make it to 90. I’ve seen 60s, even 70s, but it really drags them down.