"I think that after you finally get on campus and get to build a relationship with the guys and the people up here, it's tough to leave," he said. "It's a special place. People really don't understand that until they step up here and are a part of it.
"It's not only me. I think almost every single guy in that locker room feels the same way. We're all excited, and we're moving forward with Coach [James] Franklin, and we can't be more thrilled to do that."
Franklin, who officially was named Saturday as O'Brien's successor, met Sunday with Hackenberg and his father before he gathered the team together for his initial meeting.
"To be honest, I didn't go in there expecting to hear anything," Hackenberg said. "It was more just me finally being able to sit down with the guy that's going to be the head coach of our football team and just meet him."
When Hackenberg was a junior at Fork Union Military Academy, he spoke once or twice over the phone with Franklin on recruiting calls. He said his impressions Sunday were very favorable.
"I think he's a very personable guy," he said. "He's up-front, he's honest, he brings a lot of intensity to the room. He's very fiery. I think he's a guy that really loves the game of [football], really loves coaching it, and I can't wait to get on the field with him."
Hackenberg said he was in touch with his teammates almost every day in the two weeks from the time news broke about O'Brien's talks with the Texans to the hiring of Franklin. He said players were more anxious than uncertain about who the new coach would be.
Hackenberg was O'Brien's first commitment after he took over as head coach and stuck with the Nittany Lions after NCAA sanctions crippled the program. He said the coach's departure took him back a little bit, but he had no ill feelings.
"It's a business," he said. "He had to do what he had to do [because] family comes ahead of everything. I wish him the best of luck, and I can't thank him enough for everything he did for me and this team and this program, which is what people should be focusing on."
Lions lose recruit. Thomas Holley, a four-star defensive tackle from Brooklyn, N.Y., chose Penn State over Florida last month because of defensive line coach Larry Johnson. However, now that Johnson has left the Nittany Lions, the 6-foot-4, 295-pound Holley also has moved on, announcing Wednesday that he has changed his commitment to the Gators, multiple reports said.
Franklin filling staff. Some of Franklin's former assistants who worked for him at Vanderbilt appear to be joining him at Penn State. Quarterbacks coach Ricky Rahne and wide receivers coach Josh Gattis introduced themselves on Twitter. Five other coaches - offensive coordinator John Donovan, defensive coordinator Bob Shoop, linebackers coach Brent Pry, defensive line coach Sean Spencer, and director of performance enhancement Dwight Galt - were found on a Penn State database. The appointments will be announced after the coaches go through Penn State's hiring procedures.