Stupidity is a specific cognitive failing

> If I am trying try accomplish X, it is absolutely true that I am trying to accomplish X. Both you (the observer) and I can acknowledge this fact.

How does the observer know what someone else is trying to accomplish? The observer cannot peer into the person's mind.

> It seems much easier for the attackers to supply themselves (even in a foreign land)

That's a modern-transportation perspective. Unless the siege happens to be on a waterway and you supply that way.

Land-based logistics for pre-modern armies was _hard_. The standard solution was to keep the army on the move and forage as you went, so you kept stealing food from new peasants, but that's not an option for an army laying a siege. On the other hand, if the castle/town knew a siege was coming they would move things like livestock from the surrounding countryside inside the walls, and the grain stores were likely _already_ inside the walls.

https://en.wikipedia.org/wiki/Siege_of_Nuremberg explicitly mentions supply as a problem for the besieging army in that case, and that's an early-modern army, not premodern. http://hundredyearswar.com/Books/History/Sieges.htm also says "the siege was often lifted because the besieging commander ran out of food to feed or money to pay his troops".

In practice, what this meant is that you would not even start a siege unless you had some idea that you could ensure supply, which was the common situation.

This is still true and accepted military doctrine. We look for at least a 3:1 force ratio before considering attack a viable option. It's not exactly scientific and plenty of military historians have questioned the validity of this rule of thumb, but it still is the official doctrine, at least of the US Army. I can't speak for other countries.

Force ratio doesn't have to be strictly numerical, though. Offense can have better weapons, rely on element of surprise, and we also like to attack during really bad weather because it sucks a lot more to be dug in during a rainstorm than to be on the move. There's also some advantage in indirect fire in that it's easier for artillery to hit a stationary target than a moving one, so provided your artillery itself is mobile enough to survive counterbattery strikes, that goes to the offense. Unless the defense is so well dug in that artillery can't even affect it. So it depends on a lot of things.

But in general, defense always has the advantage. They get to choose where to fight, they can prepare their positions, they don't need to expose themselves.

I guess it's reversed in cyberwarfare if you want to think of it that way, but it's really not analogous. It's never been all that difficult to sneak a small surgical force inside an enemy perimeter, but you can't take and hold land that way, which is what attack versus defense force ratios are thinking of. This is more of a law enforcement thing, which has always relied on either having more cops than criminals or extremely harsh punishments. The issue here is we can't enforce the law against foreign actors if the host nation won't help. When actual Americans have been caught breaking into American computer systems, they've totally had the book thrown at them and I think that really has deterred domestically launched cyberattacks. It's not like the NSA can't find you, but if the only way to actually stop you is to send in Seal Team Six, that isn't worth starting a real war over.

It’s about the plasticity of your brain, but also sometimes about the opposite: holding firm mentally. Some brains hold simpler models with greater certainty. Some brains hold more complex models with less certainty. Each type witnesses instances of “stupidity” in the other; overly plastic brains (guilty) can seem aloof, imprecise; the opposite can seem too literal and closed-minded. Guess which brain votes for which political party :).

However, the caveat is that the latter brain is more suited to the world right now, with society becoming information rich and complex, and with nuanced social norms (not just x is good, y is bad). Of course I’m biased here.

I think "stupidity" as a specific set of traits that people can express either occasionally or continuously.

I don't think stupidity is the same as lack of intelligence or wisdom. Highly intelligent people can behave stupidly, too.

I spent a lot of time thinking about this. I arrived that stupidity is lack of intelligence/wisdom AND/OR inability to make use of intelligence/wisdom.

For example, one way you can be intelligent and yet stupid is if you lack self-reflection and/or are dishonest with yourself. This impairs ability to acquire wisdom -- honest observations about truth of yourself and the world around you, may make you repeat same mistakes without realizing what is causing them, etc.

Being unable to learn from your mistakes (maybe because you are not honest enough to recognize them as mistakes or recognize true causes) basically prevents you from advancing as human being. If your level of advancement is below your age you might be labeled as "stupid".