Sure is a shame to see how many people can't seem to logically reason more than one or two steps. I don't think it's a cognitive fault or some sort of congenital thing, although there is a strong correlation between height and IQ, as well as physical ability and IQ. I think it more has to do with upbringing. You know, I had a friend from an eastern European nation who told me that critical thinking was not only not taught until university, it was actively discouraged. I wonder if there's a correlation between the opinions of people in this thread and the extent of their education, and what the intellectual and cultural values were of the places where their formative educational years were spent?
I imagine that doesn't apply to you, of course. I can't imagine you can complete a PhD without critical thinking skills, in any field. What field of CS was your PhD in?