Nostalgia, defined as a sentimental longing or wistful affection for the past, has become a growing focus of research in personality and social psychology. Though it may seem counterintuitive, nostalgia has been proven to be a great motivator of future behavior. Take for example, fans of former President Barack Obama. When the 2016 election of President Donald Trump left over half of the United States' electorate reeling, it contributed to nostalgia for the days of President Obama (and his administration), even among some conservatives.