Question 6 - Why do people knowingly do stupid things?

Okay, I see what you're doing there - you put in the word 'knowingly' so I can't just say, "because they don't know any better". It also stops me from using the excuses that "it was an accident" or "because they were drunk at the time".

In that case there are only seven possible other answers. Stand back, here they all are:

1) The obvious answer - because they think the thing they're doing is clever. This would imply that the person in question was at least a bit stupid.

2) In a desperate attempt to persuade a fickle audience of bystanders that they are funny, otherwise sensible people will knowingly do stupid things, like trying to knock a policeman's helmet off his head with a snowball.

3) Some stupid things have no repercussions on the perpetrator, e.g. a senior manager forcing through a pointless project to make himself look busy and important and worthy of a promotion. Not only is this person acting knowingly, he is also being Machiavellian in creating extra work for his underlings to buy himself a slight (presumably pecunious) advantage. A more extreme example of this would be TB and GWB starting the Iraq war.

4) Some people knowingly do stupid things because their religion tells them to. I will leave it to you, dear reader, to supply your own examples for this one.

5) When acting as part of a crowd or mob, people's ability to maintain independent thought and action is diminished to such an extent that they will do stupid (and out of character) things knowingly but, technically, not as knowingly as if they were alone.

6) People will sometimes do extraordinarily daft things for a bet or other financial advantage even when sober (sometimes for a low stake, such as merely their honour). An example would be the sort of person who would juggle with chainsaws - which they do in full knowledge of what the chainsaw could do to any part of their body in the event of a slightly misjudged catch or throw.

7) Sometimes people have an onerous task which they need to perform (e.g. clearing out a load of cluttered cupboards). In order to keep up the pretence of being too busy to perform the useful (but dull) task, they create a stupid and pointless (but quite diverting) task to spend their time on instead (like starting a blog to answer random questions from anonymous members of the public).