He played late-night marathon games of Monopoly with his buddies. He went with friends on family vacations. He would hang with pals at IHOP on Fridays. He had a girlfriend. He laughed and he loved and he knew things – about jazz, cars, fantasy games.

And then Jared Loughner slipped into a world of fantasy that was no online game. Slowly but steadily, his intelligence warped into a distorted, disconnected series of obsessions.

He developed an illogical fascination with logic. Math, grammar, logic – the systems civilization has developed to make sense of the world became the means through which he expressed the confusion and pain in his increasingly lost mind.

A picture of Loughner gleaned from interviews with more than two dozen friends, classmates, teachers and neighbors, as well as from his own writing in online forums, shows no evidence that politics or government were among his defining or enduring obsessions.

Rather, his deepest, most disturbing questions were about the very nature of reality.

As a bachelor, Loughner’s father, Randy, kept mainly to himself, neighbors say, and when he did interact with others, the results were often bad: He had tiffs about incursions onto his property; he yelled at people.

In 1986, Randy Loughner married Amy Totman. According to her first cousin Judy Wackt, some members of the extended family have had mental illness.

“There’s a history in the family of what they used to call manic depression, which I guess they now call bipolar disorder,” said Wackt, who lives in Texas.

Two years after they got married, the Loughners had a son, Jared, their only child.

From his elementary years through middle school, Jared Loughner lived a life that his friends saw as little different from their own. There was something awkward about him, and he was teased more than most, but he had friends and they were often among the smarter kids in his grade.

Nasser Rey, 21, remembered Loughner as quiet and not popular in high school, but not a recluse either. They would work on assignments together and hang out, talking about hip-hop songs.

“We would get into conversations about regular stuff,” Rey said. “He was a normal dude.”

Friends say Loughner’s sophomore year was a whirlwind of change. He left behind his passion of the past few years – he stopped playing sax. He found a new love – his first real girlfriend.

He lost that love, changed his look, switched friends, discovered new interests and seemed to drift off into a world of ideas that friends found odd, irrational, disturbing.

Alex Montanaro, one of Loughner’s best friends from seventh through 10th grades, said Loughner’s “mental downfall” seemed to start after his breakup with the girlfriend, who did not respond to a request for an interview.

“Jared really became an outcast,” he said. “We allowed him around us for a while, but he started acting nutty. His friends changed from people like us to more drug-oriented people.”

By this time, Loughner had a growing fascination with dreams and alternative realities. He believed in lucid or conscious dreaming, the idea that you could consciously enter your own dream and change the path of its characters.

In the past year or so, the crumbling of what was once Loughner was clear to anyone who bothered to look. A student in Loughner’s math class at Pima Community College usually sat near the classroom door for fear that he might turn violent, according to her professor, Ben McGahee.

Within minutes of the start of McGahee’s eight-week course on algebra last June, he knew Loughner would be a problem. Loughner, who had already failed the same course, called the remedial class a “scam” and the teacher a “fraud.”

Asked to quiet down, Loughner calmly replied, “How can you deny math and not accept math?”

McGahee asked police to send an officer to his class every day. Several students asked that Loughner be given treatment or psychological testing. McGahee said he asked the counselor to “do something, but they kept telling me, ‘He hasn’t brought a weapon to class. He promised he’d be quiet. It doesn’t look like he’s hurting anybody.’ ”