Romney attended Stanford University for a year. Although the campus was becoming radicalized with the beginnings of 1960s social and political movements, he kept a clean-cut appearance and enjoyed traditional campus events. In May 1966, he was part of a counter-protest against a group staging a sit-in in the university administration building in opposition to draft status tests.
In July 1966, Romney left for 30 months in France as a Mormon missionary, a traditional duty that his father and other relatives had done before him. He arrived in Le Havre with ideas about how to change and promote the French Mission, while facing physical and economic deprivation for the first time in his life in their cramped quarters. Rules against drinking, smoking, and dating were strictly enforced. Like most Mormon missionaries, he failed to gain many converts, with the nominally Catholic but secular, wine-loving French people proving especially resistant to a religion that prohibits alcohol. He became demoralized, and later recalled it as the only time in his life when "most of what I was trying to do was rejected. In Nantes, Romney suffered a badly bruised jaw in defending two female missionaries against a horde of local rugby players. He continued to work hard, however; having grown up in Michigan rather than the more insular Utah world, Romney was better able to interact with the local population. He was promoted to zone leader in Bordeaux in early 1968 and subsequently became assistant to the mission president in Paris, the highest position a missionary could assume. Romney's hawkish views about the Vietnam War were only reinforced when the French greeted him with hostility over his country's role in it and he debated them in return. He also witnessed first-hand the May 1968 general strike and student uprisings.
In June 1968, an automobile Romney was driving was involved in a collision in southern France that seriously injured him and killed one of his passengers, the wife of the mission president. Fault for the accident was attributed completely to the driver of the other vehicle. After recovering, Romney became co-acting president of a mission demoralized and disorganized by the May civil disturbances and the car accident. Romney rallied and motivated the others and they met an ambitious goal of performing 200 baptisms for the year, the highest mark for the mission in a decade. By the end of his stint in December 1968, Romney was overseeing the work of 175 fellow members. The accident and the overall missionary experience changed Romney, giving him an appreciation for the fragility of life and the need for a seriousness of purpose, and a capacity for organization and a record of success, that he had theretofore lacked. It also represented a crucible, after having been only a half-hearted Mormon growing up: "On a mission, your faith in Jesus Christ either evaporates or it becomes much deeper. For me it became much deeper.
While he was away, Ann Davies had converted to the LDS Church, guided by George Romney, and had begun attending Brigham Young University. Mitt was nervous that she had been wooed by others while he was away, and indeed she had dated others, but at their first meeting following his return they reconnected and agreed to get married quickly. That happened on March 21, 1969, in a Bloomfield Hills civil ceremony presided over by a church elder; the following day the couple flew to Utah for a wedding ceremony at the Salt Lake Temple.
Romney began attending Brigham Young too. He had missed much of the tumultuous American anti-Vietnam War movement while away, and was surprised to learn that his father had turned against the war during his ill-fated 1968 presidential campaign. Regarding the military draft, Romney had initially gotten a student deferment, then like most other Mormon missionaries had received a ministerial deferment while in France, then got another student deferment. When those ran out, his high number in the December 1969 draft lottery (300) meant he would not be selected.
At culturally conservative Brigham Young, Romney continued to be sheltered from much of the upheaval of the era, and did not join the few protests against the war or the LDS Church's policy against giving full membership to blacks. He became president and successful fundraiser for the all-male Cougar Club and showed a new-found discipline in his studies. In his senior year he took leave to work as driver and advance man for his mother Lenore Romney's eventually unsuccessful 1970 campaign for U.S. Senator from Michigan. He graduated from Brigham Young in 1971, earning a Bachelor of Arts in English and giving commencement addresses to both his own College of Humanities and to the whole university.
The Romneys' first son, Tagg, was born in 1970 while both were undergraduates at Brigham Young and living in a basement apartment. They subsequently had Matt (1971), Josh (1975), Ben (1978), and Craig. Ann Romney's work as a stay-at-home mom would enable her husband to pursue his career.
Romney still wanted to pursue a business path, but his father, by now serving in President Richard Nixon's cabinet as U.S. Secretary of Housing and Urban Development, advised that a law degree would be valuable. Thus Romney became one of only 15 students to enroll at the recently created joint Juris Doctor/Master of Business Administration four-year program coordinated between Harvard Law School and Harvard Business School. Fellow students noted Romney's strong work ethic and buttoned-down appearance; he lived in a Belmont, Massachusetts house with Ann and by now two children. He graduated in 1975 cum laude from the law school, representing a standing in the top third of that class, and was named a Baker Scholar for graduating in the top five percent of his business school class.