Why are 98% of people just plain stupid?

[Peaches]

I've seen several levels of what could be classified as "stupidity".

a) Those who think they know it all and therefore there's no reason to learn anything more. They usually have high IQ's and are considered "smart", yet to me, this is VERY stupid.

b ) Those who just don't want to learn. They have decided they're happy where they are and there's no need to go further. IME, these are usually lower middle class blue collar workers. They do NOT have high IQ's or much education and they have no desire to learn anything in any capacity.

c) Those who others consider "stupid" because of lack of education, living conditions, etc. For instance, the couple who runs our subdivision - neither have much of an education, they live simply, don't have much money and probably don't make much money. But they are each VERY smart: She knows how to deal with just about everyone who crosses her path (she works the front gate) and he can solve most civil engineering problems, electrical, construction, etc. They are both learning at every opportunity, just not in a structured environment. Yet again, many people would look at them as "stupid" because they will always be lower middle class and don't have a formal education.

d) Those who CAN'T learn. I put myself in this category regarding math/numbers. :P