What we learn before we turn eighteen becomes the common sense of our later life. Just as the vast majority of people after careful consideration of all the candidates and the issues end up voting for the same party as their parents so too most people can never break free of the paradigm impressed upon them as they grew up.
Many people repeat the time worn phrase, "Those who don't learn from History are doomed to repeat it." As a person who has read and studied History on a daily basis for more than fifty years, one of the major lessons I have learned is that the general public never learn from History, mainly because they don't read or study it. Perhaps they were spoon-fed a few classes as they meandered through the American education factory but they never tried to do more than memorize enough to regurgitate at the proper time to move on. What was presented was based upon biased agenda of whoever picked the texts and prepared the lessons. The only way to get a broader view is to read and study.