Humans are supposed to be clever creatures, but their stupidity is pretty interesting too. Where else can you find beings who will completely ignore instinct in favour of their own stupidity? The Darwin Awards obviously list idiots in their greatest achievement of stupidities. A lot of stupidities listed on the site generally lead cleansing of the human genome of their existence in the inheritance line.
How stupid can people get? Ignoring the bleeding obvious can be one of them. I am among those who are among those incapable of seeing the obvious. I am the kind of idiot that takes the tutorial sheet, blast my entire way through, and then sees the easier way out later. It's so interesting see my stupidity occur.
Of course, there are many kind of stupidity. Mine seems to come from lack of common sense to begin with. That is, I lack fundamental logic within my mentality. It might sound odd, but I do lack quite an amount of what people would call 'common sense'. A lot of my common sense is emulated - hence there will be a lack of 'common sense' in certain situations when emulation will not function. If you know me, there might have been times when you would've noticed such anomalies. :D
However, there are also a lot of cases where people with common sense are willing to ignore them. It would be incorrect to say I envy some of these people, since I would consider it foolish to push aside basic human knowledge in favour of something else more desirable to them.
In my opinion, stupidity is when a human being lacks or refuses to heed common sense in favour of his or her own agenda. Since I'm getting sleepy, and I should go to sleep, I'll stop here. No point ignoring signals from my body to go to sleep. As for my agenda about stupidity, it'll have to wait another day. :D
(For the record, lacking common sense is OK. Refusing to use it is another story for another day.)