You seem to be forgetting the predicament you may be putting someone else in.
Not at all. I'm very aware of it. But we can't and shouldn't assume that our own choices should be applied to others. Life is for living, and living entails risk.
Or kids seeing an adult riding trails and jumps with no helmet, lets say that influence leaves the helmet their parent bought at the side of a jump, and the kid hurts his head, I feel it is part of social responsibility to set an example.
It's a possible scenario, but kids are tough, and they learn from their mistakes. What about the hypothetical kid who comes to love mountain biking by watching your helmeted example, takes a rough descent, helmeted, a little too fast, and ends up in a wheelchair?
Now, I didn't say anything about jumping
A lot of this does not seem to be tested against or have any proven protection. I remember seeing early tests which involved an impact straight on top of the helmet,which is nothing like an abrasive sideways impact with weight and leverage at speed.
I agree, which is another reason I object to the suggestion that it's a no-brainer. We just don't have the data.
Personally I still believe for the majority of riders and rider environments that a decent bicycle helmet is a good and responsible habit.
I'm more than happy for you to hold that opinion.
Calmes dans le demi-jour
Que les branches hautes font,
Pénétrons bien notre amour
De ce silence profond.