Taking a half day off from attending this year's World Cup, Jackson put himself in a cage off the coast of Cape Town, South Africa and let great white sharks swim around him and hopefully not through him. He survived.
Seeing those predatory eating machines in action opened his mind to a lot of thoughts. Sharks ultimately survive because they control their environment. Jackson is a running back who often depends on the blocking around him, but he has some control of the situation because he has the ball.
What concerns Jackson is a new generation of running backs who are accepting roles in multiple-back formations. Last season, only nine running backs had 250 or more carries and only six had more than 300 carries. What used to be a position at which the onus was put on one featured back -- ESPN's Merril Hoge uses the term "factor back" -- is becoming a place for schools of replaceable backs.
It has concerned Jackson to the point of making a statement to those young backs.
"I think it's a lost art that I want to try to carry on until the next phase of running backs come," Jackson said. "I really pride myself in being one of the rare guys who stay on the field for three downs."
Jackson is secure in so many areas. He's 27 and the league's highest-paid running back with a five-year, $43.1 million contract. He's been around the league for six years and has 1,548 carries, 6,707 yards and 41 rushing touchdowns. He's at the age and carry level where backs start to set themselves up for extinction, but he's rededicated himself.
Jackson couldn't be in better shape. He's added eight pounds of muscle during the offseason and now is at 244 pounds with only 5 percent body fat. Jackson spent extra time strengthening his back to better absorb the pounding.
With the Rams expected to use rookie quarterback Sam Bradford, Jackson knows he must be ready for 20 or more carries and five or more catches per game. Jackson knows his assignment, but he wants to make a statement to the other backs who should try to follow his lead.
"I'm going to look at it from a business point of view that not many people are thinking about," Jackson said. "When you have so many guys, you water down your value of the backs. I don't think so many of these young guys realize that. When you share the load and you are up for a contract, what is your argument?"
Only nine backs make more than $5 million a year, and Jackson doesn't see a lot of new backs who will command big dollars. Unlike players at other positions, backs have a short NFL life span. Once they reach 28 or 29 years old, backs are destined to be replaced by most teams.
Jackson knows that the likelihood of his getting a new, big contract isn't great, so all he can work on now is what he can do for the Rams and his legacy. Jackson wants to be a back whom others try to copy because he doesn't want to leave the field. He's the shark, not the school of fish being eaten up by the sharks.
"I'm just trying to pave a new way," Jackson said. "I'm trying to find a new way for coaches and general managers to look at it. I want to show you can get a back who is prepared to endure."
Like most backs, Jackson watched what happened with Shaun Alexander of the Seahawks. Alexander helped carry the Seahawks to a Super Bowl and four division titles. His second contract didn't come until 2006, when he was 29 and had 1,717 carries.
Then general manager Tim Ruskell gave Alexander the contract as a reward for past services, but everyone around the league knew the Seahawks' back wouldn't fulfill it. Alexander didn't have a 1,000-yard season in his final two years in Seattle and is now out the league still thinking he can play. Jackson wants to show by example that a back can stay on the field, going against the trend of shared backfields.
"If you are good enough to get a second deal, you're not getting a third deal," Jackson said. "You see what happened to Shaun Alexander. I want coaches and general managers to look at it a different way, and I want to be the example."
Jackson has set a goal to play at a high level for five more seasons. He hopes to give Bradford a back to depend on to make the rookie's transition as easy as possible. Jackson averaged 21.6 carries a game last season and wouldn't mind getting 25 carries a game to help his young quarterback.
Financially secure and fit for anything, Jackson is ready for the heavy workload and wishes others would follow. He's all for the preservation of the workhorse running back.
John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com.