Some of the elements in the love story have changed over time. In the ancient world and during the Middle Ages, love stories did not have happy endings, and they focused on love outside of social and economic status. This was an innovation at that time, because most marriages were arranged and the partners were of the same social class. Beginning in the late Middle Ages and the Renaissance, love stories began to have happy endings, because marriage was coming to be rooted in feelings of truelove and couples came together by personal choice. Modern love stories are influenced by Hollywood, and often feature pre-marital and extra-marital sexual relationships, and single parents with children. Over the years, a conventional format was followed. As entertainment and moral values changed, however, the distinction between convention and innovation became blurred. The conventional love story formula has several elements: The couple wants to be together. Often it is love at first sight.