Tagg's early-adolescent struggles were emotional in nature, which meant they played more to his mother's strengths than his father's. With a few exceptions, "he's not emotional at all," Tagg says. "She runs on emotion, he runs on logic."

After a few years, the tensions lifted, as Mitt learned to give Tagg more space, and Tagg began to regret how he'd been behaving. By the time he was 15, the arguments stopped, and Tagg was once again looking at his father and seeing his hero.

A few years later, Ann would be mocked for her public claim that she and Mitt had never had an argument, which sounded preposterous to the ears of many married mortals. But Tagg says it's not that his parents never disagree.

"I know there are things that she says that he doesn't agree with sometimes, and I see him kind of bite his tongue. But I know that they go and discuss it in private. He doesn't ever contradict my mother in public."

In that way, the relationship between Mitt and Ann differed from the one between Mitt's parents. Despite their lifetime of devotion, George and Lenore had no problem airing their disagreements, especially in later years, according to Tagg. "Listen, they fought like cats and dogs. We called them 'The Bickersons."'

As the 1980s wore on, Mitt's responsibilities grew both at work and in the church, where he was promoted to stake president, overseeing about a dozen congregations. And his Midas touch at Bain Capital was helping to make him rich.

Yet Mitt eschewed the trappings of wealth. The family had no cook or full-time maid. And Mitt continued to drive a dented Chevy Caprice Classic nicknamed "the gray grunt."

His sons urged him to buy a luxury car, but he refused. Still, they had no idea how much money he had.

Then, in 1989, Mitt and Ann allowed their first bout of conspicuous spending, plunking down $1.25 million for a stately five-bedroom house up the road, enlarging and renovating it, plus installing a pool and tennis court. At the time, Tagg was in France, following in his father's footsteps as a Mormon missionary. After his parents sent him a photo of their new place, he asked his father, "How can you afford that house?"

Before long, his father could have afforded to buy up the whole street, as he built a fortune that two of his former partners now estimate to be more than $400 million.

In 1990, Romney began a turnaround effort at Bain & Company, the much larger — but fast sinking — sister company to Bain Capital. A few years later, he was back full time at his old firm. It had been reorganized as Bain Capital Inc., with Romney as CEO and sole owner. And it had matured, meaning far bigger paychecks were on their way.

Swinging at a giant