"This is unbelievable."
Pronouncing himself as the new leader of the Penn State family on Saturday, O'Brien - who finalized his contract on Friday after a two-month search by the school to replace Joe Paterno - issued a statement, then took questions from the media before posing for pictures. He reiterated his intention to remain offensive coordinator for the New England Patriots for the duration of their playoff run. New England has a bye this weekend.
O'Brien, 42, steps in for Paterno, fired Nov. 9 in the aftermath of child sex abuse charges against retired assistant coach Jerry Sandusky. Not only is O'Brien replacing Division I's winningest coach, but he must also guide a program shrouded in uncertainty. Besides the criminal investigation into Sandusky, the NCAA has launched its own inquiry.
"I feel like I'm a mentally tough guy right now," O'Brien said. "I feel like I'm the right guy."
O'Brien said he will compile his staff over the next two or three days, and get the assistants on the recruiting trail immediately while he works with New England. He will retain assistant coach Larry Johnson from Paterno's offense.
"I'm going to surround myself with good people," O'Brien said, "and I'm excited to do that."
He received a five-year contact with a base compensation starting at $950,000 with a 5-percent salary increase each season. O'Brien was also to receive another $1 million a year for radio and television work, as well as a $350,000 Nike contract.
O'Brien joined New England in 2007 following 14 seasons on the college level, including stops at Duke, Maryland and Georgia Tech. He played football at Brown - Paterno's alma mater.
The Patriots are third in the NFL overall in scoring (32.1 points per game), and second in total offense (428 yards) and passing (317.8 yards).
Penn State finished a 9-4 campaign with a 30-14 loss in the TicketCity Bowl to Houston on Jan. 2. The Nittany Lions relied on defense much of the year after the offense struggled with a two-quarterback system.
In a statement, President Rodney Erickson commended O'Brien as someone who would "maintain the school's commitment to excellence on the field and in the classroom. We have that leader in Coach O'Brien."
O'Brien has no previous ties to Penn State and a proud program tarnished by a scandal that also led to the departure of President Graham Spanier.
O'Brien and Paterno do share at least one connection though - both coaches attended Brown University.
Stepping to the podium at his introductory news conference before a throng of media, O'Brien surveyed the crowd and found his young son, Michael, wearing the blue No. 25 jersey of tailback Silas Redd.
"I can't wait to get going on this," he said, "get everyone headed in the right direction."
This was O'Brien's first year coordinating the Patriots' legendary offense, but he has also coached star quarterback Tom Brady since 2009 and spent 2008 coaching receivers.
O'Brien recently was in the spotlight when he and Brady got into a heated argument, shown on national television, after Brady threw an interception in the end zone in the fourth quarter of the Patriots' 34-27 win over the Washington Redskins on Dec. 11.
He was asked about the incident and his relationship with Brady. He spoke of the Pro Bowl quarterback in glowing terms, before addressing the scene on the sideline.
"Football is an emotional game," he said.
New England closed the regular season on an eight-game winning streak, and scored 513 points, the most in the AFC. Brady threw for 5,235 yards and 39 touchdowns, with just 12 interceptions.
Brady has described O'Brien as a great coach and friend. Receiver Julian Edelman on Friday in Foxborough, Mass., described O'Brien as charismatic and emotional.
On Saturday, New England coach Bill Belichick, who O'Brien thanked during his press conference, issued a statement.
"Over the course of his long coaching career, Bill O'Brien has met every personal and professional challenge head on with great passion and competitiveness. I expect Bill to draw on his deep background in college football and the NFL to continue attracting and developing top players," Belichick said. "For five years, Bill's outstanding work with our quarterbacks and entire offense has led to record-setting performances. His presence and command before our team has grown into that of an inspirational leader.
"This is a great match between a storied program and an old-school football coach. Bill will be up to the task and I couldn't be happier for him."