Humans are driven heavily by certain "heuristics and biases". An interesting chapter-length introduction is available at http://www.singinst.org/upload/cognitive-biases.pdf . You'll be surprised at the results, and you'll see that you've fallen victim to many or all of these biases. He cites some books for more info on the subject (but I haven't read them).

Also, check out the excellent blog http://overcomingbias.com . (Warning: the blog has many authors, and some of the posters are more exciting than the others)