I gave one example which is critical thinking, but I'd also say it includes things like self-awareness. Some people just are not. I don't know how else to describe it other than it seems like they literally just do not think before they act. There's a level one worse than "doesn't consider the consequences of their actions" and that's "doesn't consider their actions at all". Of course, any definition I use for this is going to be met with "but that can happen on its own in people who think perfectly fine". That's not what I'm talking about. I'm talking about when there's simply no sign that thinking happens. Like the only thing their brain does is habits and shortcuts. They're simply not an intellectual, curious, open-minded, or rational individual. I don't mean to be insulting to anyone, but when someone is simply none of these things and there is absolutely no openness or desire to improve, then I conclude that there may as well not be any thought. This isn't equivalent to a lack of intelligence, skill or talent. It's just wasted potential that most likely can no longer be realized.
I would say anyone who enjoys HN probably doesn't have a lack of thought. It's difficult for me to precisely define what thought even is, because I'm not talking about the subjective experience of thinking (internal monologue/dialogue or so on). I'm talking about whatever holds the fundamental ability for consideration of basically anything. You don't necessarily get that for free. Brains are generally extremely good at optimizing and especially neurotypical ones can indeed find a way to live without thought. (I would say autistic neurotypes could find it more difficult due to the detail-oriented thinking. It's more difficult to put smaller blocks together without developing the ability to think about them.)
> There's the meta of learning how to learn, but that is its own skill-set. Most people get by with instructors and classes.
See, how to learn can actually differ by neurotype. That's not really what I'm talking about, though. It's not people who are incapable of learning, I'm sure they can learn all sorts of things. It's that they're incapable of thinking about what they've learned. You can show them how to do something and they'll do it, they can have goals and executive function (even if they can't explain it), and they can probably still figure things out by trial and error. But ask them to explain any of these things and chances are they won't even know why they did them, just that they did and it got them what they wanted and that's all they care about.