He's been in nearly every imaginable situation everything over his nine seasons marked by three MVP awards, three trips to the NBA Finals with two teams and one decision that changed everything.
And now this: For the first time, he's one win from a championship.
''I have a job to do,'' James said Wednesday. ''And my job is not done.''
The job might get done Thursday night, when the Miami Heat - up 3-1 in this title series - host the Oklahoma City Thunder in Game 5 of the finals. Even after leaving Game 4 late with a cramp, James is on the cusp of finally becoming a champ. He was swept in his first finals trip in 2007, then he and the Heat fell in the 2011 title series in six games.
After countless ups and downs, the 804th game of his career may be the one that ends his title quest.
''I have no idea what I'll say before we go out there,'' said James, who got treatment against Wednesday but said soreness that followed the cramps in his left leg was easing. ''It kind of just comes to me when I'm getting ready to go out there and stand on the floor. But hopefully whatever I say will inspire our guys to go out and give a good show.''
James joined the Heat in 2010 after Miami convinced him that he would have enough help to win a championship - more specifically, that he wouldn't have to carry the load by himself, like he did so many times in Cleveland over his first seven seasons. The Heat were keeping Dwyane Wade, adding Chris Bosh and filling out the roster with a mix that would be best described as unconventional.
If that axiom - more options are better - actually needed to be proven, it was done in Game 4. James could not finish the game, though he returned after the first wave of cramps hit and delivered a key 3-pointer. With James watching the final minute, Wade and Mario Chalmers helped close out the Thunder, Miami winning 104-98 to move one win away from the franchise's second championship.
''This team, I think we understand that the moment is the biggest thing,'' Wade said. ''We're excited about the possibility of playing better, doing things better defensively, but also offensively. We don't feel like we've played our best game yet, and we feel that's still to come.''
The Thunder expect the same from themselves. At least, they hope that's the case.
No team in finals history has successfully rallied from a 3-1 series deficit, or even forced as much as a Game 7 when presented with that scenario since the league went to its current 2-3-2 finals format in 1985. But Oklahoma City's losses in this series - in each of the last three games - have come by four, six and six points, respectively.
A play here, a bounce there, this series might look a whole lot different. And that's why the Western Conference champions are conceding nothing.
''We didn't get here just to make it here and say we did,'' Thunder star Kevin Durant said. ''We made it to the finals. We want to come in here and we want to try to get a title. It's all about keep competing until that last buzzer sounds, and that's what we're going to do. That's the type of city we play for, a city that never gives up. That's the type of team we are. We're going to keep fighting, keep fighting, and we'll see what happens tomorrow.''
Russell Westbrook scored 43 points for the Thunder in Game 4 - and they were for naught. It was the second time in these playoffs that someone had scored at least that many against the Heat. And like Boston's Rajon Rondo, who dropped 44 on Miami in the Eastern Conference finals, Westbrook walked off the court with a loss.
''I can't really be too happy about what I (did) because we didn't win,'' Westbrook said. ''It doesn't matter. There's probably a lot of different guys that put up so many points or so many amount of rebounds, and nobody remembers it. The only thing that people remember is if you won the championship, and that's all that matters.''
It might take more than leg cramps to keep James off the court for too long in Game 5.
He was his usual self in practice on Wednesday, laughing with teammates while shooting a few free throws, looking at ease. And most importantly to Miami, he was moving without too much pain.
James had to be carried off the court in the fourth quarter of Game 4, unable to walk to the bench. A lot of fluids and rest later, some of the bounce was back in his step on Wednesday.
I feel a lot better than I did last night. That's clear,'' James said. ''I'm still a little (sore) because of the muscles just kind of being at an intense level, very tight. I'm still sore. I was able to get some treatment last night. I was able to get some treatment this morning. ... And also with the game being basically at midnight tomorrow night, I have all day tomorrow, too, to prepare. I should be fine by tomorrow night.''
It's a 9 p.m. tipoff, actually, but the point is made.
By Thursday night, James will be ready for the championship stage. And so will his team. What started on Christmas Day in Dallas, watching the Mavericks hoist the banner that will forever commemorate their championship celebration on Miami's home floor last year, could end as the perfect turnaround story for the Heat.
''You've got to absolutely immerse yourself into the process and the focus,'' Heat coach Erik Spoelstra said. ''It's Game 5. We want to treat it as a Game 7. But we are preparing for Game 5 to protect our home court and to take care of that business. It's been well documented the experience we went through last year and the pain and all that. It doesn't guarantee anything. Experience is a great teacher. You know, hopefully all those experiences will help us.''
James says they've already helped him.
He could not have seemed more relaxed on Wednesday. The chance he's waited nine years for comes on Thursday night, and James appeared totally comfortable in anticipation of that moment.
I've experienced some things in my long but short career, and I'm able to make it better of myself throughout these playoffs and throughout this whole year, and that's on and off the court,'' James said. ''I'm just happy that I'm able to be in this position today and be back in this stage where I can do the things that I can do to make this team proud, make this organization proud, and we'll see what happens.''