Harry How/Allsport Tom Brady

New England Patriots quarterback Tom Brady just won a record fifth Super Bowl on Sunday night. He's now being called the greatest of all time. But you wouldn't have guessed that 25 years ago, when Brady had to fight for playing time on his high school junior varsity, a team that had not won a game or even scored a touchdown all year.

Three years later, Brady was the varsity's starting quarterback. But to get attention, he had to send out dozens of highlight tapes. When Michigan offered a scholarship, he took it but found himself buried on the depth chart at seventh-string. His junior season it looked like Brady might finally get the job to himself, but had to battle a freshman phenom named Drew Henson for the job.

Tom Brady With Super Bowl LI Trophy

During Autograph Day that year, before Henson had even played a down, he stood under the goal posts, signing his name on anything fans asked him to. They formed a line that stretched out to mid-field. Brady, meanwhile, stood in the tunnel, with no one asking him to sign anything.

When the season started, the two quarterbacks split time. "That meant if Tom made a mistake, he'd get pulled -- and it got to him," his old friend Jay Flannelly told me. During the 1998 Syracuse game, when Donovan McNab was running wild, the fans booed Brady and cheered for Henson.

In Brady's senior season, they were still splitting time, but each time Henson dug a hole for Michigan, Brady would get them out of it, leading comeback victories against Notre Dame, Penn State, Ohio State and Alabama in the Orange Bowl.

Brady did all this with no outbursts and no ego. He lived in an apartment building with a single washer and dryer in the basement. When another student had left a load of laundry in the dryer too long, and went down to get it, he expected to see his clothes in a pile. Instead, he saw Tom Brady standing at the dryer folding his T-shirts, and leaving them in a neat stack. An entitled jock, he was not.

Despite Brady's stellar senior year, NFL scouts thought he was too skinny and too slow. In the 2000 draft, Brady expected to go in the second or third round, then watched six quarterbacks get picked before him. When New England finally took Brady in the sixth round, with the 199th pick overall, Brady felt humiliated.

Tom Brady, Robert Kraft

I once congratulated Patriots owner Robert Kraft for picking Brady, when nobody else did. Kraft said, "Don't give us too much credit. Don't forget Antwan Harris."

I said, "Who's Antwan Harris?"

He said, "The guy we picked before Tom Brady."

Harris started a total of two games in the NFL. And no, you haven't heard of him, either.

Brady started his first season as the fourth-string quarterback. He sat in the stands, watching starter Drew Bledsoe, and eating hot dogs. But before the end of his rookie season, Brady worked his way up to second-string. When Bledsoe went down early the next year, Brady led the Patriots to their first Super Bowl title. Even after Brady won his third Super Bowl in his fourth season as a starter, he remained as hungry as the kid fighting his way up the depth chart.

Bill O'Brien joined the Patriots' staff in 2007, then worked his way up to offensive coordinator from 2009 through 2011, before becoming head coach at Penn State, then the Texans. When I asked O'Brien to explain Brady's success, he told me, "Tom is a very, very bright guy, and the ultimate competitor – the greatest competitor that's ever played at that position. Don't shortchange him as an athlete, either. He's got great feet, and he works at taking care of his body, with a very strict diet and exercise. And fourth, he has a great memory, he learns from experience, and can process information very quickly."

Tom Brady

Brady's also considered a great teammate. When O'Brien became Brady's offensive coordinator, Brady told him, "I want to be coached." But, O'Brien said, that doesn't mean Brady's easy to coach. "He watches almost as much film as the coaches, and retains more of it than anyone."

So, when O'Brien gave his New England quarterbacks the game plan against Buffalo in 2010, he told them Buffalo never would get suckered by a certain scheme. Brady spoke up: "We ran this play before on these guys when their staff had a similar coaching philosophy, so it'll work."

"When was that?" O'Brien asked.

"2002." Brady said.

"Eight years ago?" O'Brien responded, incredulously. "Get out of here!"

Brady said New England had faced second-and-two, on the 35-yard line, when he hit Troy Brown on a crossing pattern.

"No way you remember that," O'Brien insisted.

"Put it on!" Brady said.

So O'Brien loaded the plays from 2002. Sure enough, early in the game, the Pats faced second-and-two, and Buffalo tried to defend them with the exact scheme Brady claimed they had.

Tom Brady

"I don't think anyone in this league," O'Brien concludes, "has a better memory than Tom's."

Brady has since put all these traits to use in leading the Patriots to a total of seven Super Bowls, winning five. But Sunday's was the best. He brought the Patriots back from 25 points down to win in overtime. Along the way, he set just about every record that he hadn't set before. Good luck to the next generation.

Now, almost everybody is calling Brady the "Greatest of All Time." He doesn't like it, but that's a problem the former back-up just might have to live with.

John U. Bacon is the author of four New York Times bestsellers. His latest book, Endzone: The Rise, Fall and Return of Michigan Football, is now available in paperback with an update covering the 2015 season and 2016 off-season. He gives weekly commentary on Michigan Radio, teaches at the University of Michigan and Northwestern's Medill School of Journalism, and speaks nationwide on leadership and diversity. Learn more at JohnUBacon.com, and follow him on Twitter @johnubacon.