Asked to give an example, Jackson mentions the daily grind of practices, meetings, and film study.
"I didn't really think the schedules would be as long as they are," Jackson said earlier this week. "It's like a real 9 to 5 [job]. I thought you would really be playing football on Sundays. But it's really like a regular job, and that threw me off."
Jackson was 21 when the Eagles selected him in the second round of the 2008 draft. More than four years later, he gets the business side of the NFL as much as any player. He's been fined for excessive touchdown celebrations and even for wearing his socks the wrong way.
And then there was the contract; the one he felt he deserved after three unprecedented years for an Eagles receiver; the extension he and the team could not agree upon before last season; the one everyone, including Jackson, now admits became a distraction.
"I kind of had to grasp everything on the run but at the same time still have fun and be the kid that dreamed about this my whole life," Jackson said during a rare one-on-one interview. "Sometimes people [saw] something that I did and probably wanted to judge it or say crazy things about it. But you got to realize this is a young man, fresh out of college, coming into a huge level, being in the NFL."
Jackson has his big contract now - five years, potentially $51 million, $17 million of it guaranteed - and, with the distractions of last season long gone, he is expected to return to form and possibly reach greater heights.
This interview was supposed to be strictly about X's and O's. Jackson said he was burned two weeks ago when a comment he gave ESPN was interpreted as the receiver's saying he had not given 100 percent last season.
"The media love twisting my damn words up," he tweeted after the report. "An they always wondering why I don't want to talk . . ."
So it's a minor miracle that he agreed to sit down on this Monday before the season opener. When it was time to talk, Jackson interrupted the walk to the public relations department at the NovaCare Complex and cut into an office across from the locker room.
"Let's do this here," he said, "where I'm comfortable."
Dedication to his craft
Jackson, dressed in gray sweats and matching hoodie, was offered the cozy-looking chair behind the desk, but he plopped down in one on the other side of the room. Just as a reporter headed for the cozy chair, Jackson smiled and pointed to the square chair next to his.
"Sit here," he said.
The chairs could not have been any closer.
The questions started off strictly about football.
Andy Reid had spoken of a new route system for Jackson this season. The receiver said he did not know anything about that. Michael Vick had recently mentioned the Eagles were trying to find ways to get the ball in Jackson's hands more often. The receiver said he'll do whatever the team asks of him.
Jackson was then asked what motivated him as he enters his fifth season - one some said he would never reach at 5-foot-10, 175 pounds - and the conversation shifted, and the 25-year-old turned introspective.
A Super Bowl, the Hall of Fame, winning, Jackson said, motivates him. The memory of his father, Bill, who died three years ago from pancreatic cancer, still drives him.
"A day doesn't go by that I don't think about him," Jackson said as he twisted strands of his goatee into a knot. "He's left some things in me that I got from him being a man - hard work and putting it all in."
Jackson prides himself on his dedication to his craft. It's why the ESPN report bothered him so. He stays after practice as often as most Eagles players.
Last week, assistant coach Duce Staley convinced running backs LeSean McCoy and Stanley Havili to run 20 half-gassers - field-long sprints - after a two-hour long practice. Jackson joined them.
"I'm a firm believer in," he said, "if you put it in, you're going to get it out."
His critics, however, say that if Jackson wasn't mentally putting it in during a contract year, what's to say he will now that he's been paid?
"I'm never content regardless of me having a contract. I'm not content," Jackson said. "I want to go out there and still work hard and be known [as] a guy that puts it on the line for his team. That's something I've always done since I've been here."
'Like a microscope'
Even last year, when he was supposedly not all there - "His mind was in left field," Vick said - Jackson still put up numbers in line with the rest of his career. But something was missing. Every move he made was dissected. It's been that way since he arrived in Philadelphia.
"A lot of times I tend to think back to me having nothing, growing up in an area where I didn't know nothing but to do what I had to do to get it," Jackson said Monday. "Now that I have it, I just got to be smart. It's like a microscope. Every little thing you do the whole world knows about it."
Jackson's world used to be much smaller. He spent his formative years living in the Crenshaw District of South Central Los Angeles. But he's had to transition into adulthood under the spotlight of the NFL. He's made mistakes. But Reid and others said he's maturing.
"Everybody has seen him in here growing up," Reid said. "It's that youthful energy and that tenacity that he has that's allowed him at  pounds to be an NFL player. You need a little bit of that grit and that edge."
Jackson isn't looking for sympathy, although it would be nice to be understood.
"It's just kind of the way I carry myself. People misjudge it sometimes and think I'm selfish or I'm quiet or I'm rude because I don't talk," he said. "It's just coming from where I came from, the things that I saw, the obstacles that I had to face in life that brought me to where I am today."
Contact Jeff McLane at 215-854-4745 or firstname.lastname@example.org, or follow on Twitter @Jeff_McLane.