Some years just seem to have less impact than others. But 2011 held the Arab Spring, the death of Osama bin Laden, Occupy Wall Street, protests against austerity measures and the ousting of Berlusconi, as well as the end of the Iraq War. Which events of the past year will make it to the history textbooks, and which will be esoteric stories we confuse our grandkids with? Kenneth Davis, author of “Don’t Know Much About History,” talks about the biggest stories of the year.