The short version was that Epstein, who is legendary for his intense work habits, could no longer give the Red Sox everything he had.
"You have to devote yourself to it completely," said Epstein. "You have to believe in every aspect of it. And in the end, after a long period of reflection about myself and the organization, I decided I could no longer put my whole heart and soul into it."
Naturally, everyone wanted to know why that was the case. Epstein could only speak in broad terms.
Because he is a man of integrity -- something clear throughout his three years heading the front office of the team he feverishly rooted for during his youth -- Epstein didn't get overly specific. In other words, he didn't wish to point fingers at anyone or anything.
After thorough negotiations the last couple of weeks with club president/CEO Larry Lucchino and principal owner John W. Henry, Epstein came to the conclusion that a job he once seemed destined for -- never more so than when he was drenched in champagne the night of Oct. 27, 2004 -- was no longer a fit.
He told his bosses he would make a decision by 1 p.m. on Monday (11 hours before his contract expired), and he did just that, only it wasn't the one they were hoping for.
"I think a lot of things happened during the end of this negotiation that caused me to think more closely about the situation, think about myself, think about the organization and whether it was the right fit," said Epstein. "Again, in the end, I decided that the right thing to do was to move on."
Part of moving on was to have closure with the media, some of which had been staking him out with such vigor that Epstein actually needed to put on a Halloween costume to leave his Fenway Park office Monday night.
"I understand there's been some interest in talking to me over the last couple of days, as evidenced by the cameras outside my house and the fact that I left in a gorilla suit the other day," said Epstein. "That thing's getting itchy, so I thought I would just come here and try to answer your questions today."
He tried, as best he could, but some will always remain. What is clear is that Epstein is firm in his decision to move on with his professional life, unsure of what the next step will be.
Yes, Epstein wants to stay in baseball. Will he be a general manager in 2006?
Maybe, maybe not. He said that his only priority this week is to help the baseball operations department of the Red Sox prepare for next week's general managers meetings. Once he leaves Yawkey Way for good -- probably by this weekend -- Epstein will then start the process of figuring out what he wants to do next.
Henry seemed visibly crushed by Epstein's decision to leave.
"Never in my wildest dreams did I think this would ever happen," said Henry. "I had this romantic notion that Theo was going to be our general manager for the rest of my life. This is a great, great loss."
Though Henry spoke with Epstein every step of the way during this process, even he admitted that he didn't completely understand his former general manager's decision to leave. And yes, he tried to talk him out of it. Probably too many times to count.
There continues to be rampant speculation about why Epstein left.
Had Epstein suffered a downturn in his relationship with mentor Lucchino so severe that he could no longer work for him? Epstein said that it was wholly unfair to pin his desire to leave on one person.
"My relationship with Larry is one that spanned about 14 years; we've had a very successful working relationship," said Epstein. "I think Larry and I like each other. As with any long-term relationship, there are complexities, there are ups and down, there are occasionally times where you have philosophical differences. In the end, I want what's best for Larry. I wish him well in the future. And when I look back, he's done a lot for me. I owe him quite a bit. And I take that to the heart. In the end, 30 years from now when I look back on my relationship with Larry Lucchino, I'm going to see it as a positive influence in my life.
"Look, focusing too much on any one person or any one factor is not appropriate here. This decision was not something I took lightly. And it was based on a variety of factors. Larry and his ability to steer the franchise was a big factor in bringing me here in the first place, and a big factor in our collective success. It's inappropriate to focus on any one person."
Was the suffocating environment of being a celebrity in Boston no longer manageable? Epstein admitted it was a challenge at times, but said it was not a factor in his decision to leave.
Because Epstein has been so noted for working around the clock, it was fair to wonder whether he simply reached a point of burnout. That, he stated emphatically, was not the case.
"No, I am not burned out," said Epstein. "I have tremendous passion for the game. I have tremendous dedication to the game. I believe that I will find myself in a position of leadership with an organization again in the future, but I have no immediate plans. My goal for the rest of this week is to help the organization with the transition and to help the baseball operations staff that I care so much about get ready for the general managers meetings."
Many players, including captain Jason Varitek, ace Curt Schilling, slugger David Ortiz and free agent center fielder Johnny Damon, have spoken of their affection for Epstein in recent days, and thus, were left disappointed by his exit.
How did that make Epstein feel?
"I guess it makes me feel good to hear that I'm respected and liked by the people I worked with, and I feel the same way about them," Epstein said. "It's bittersweet because it makes you feel ... it reminds you how difficult it is to leave. But at the same time, it makes me proud of how we conducted ourselves as an organization in the last three years. I think we have very high expectations of our players on and off the field, and put a lot of trust in them, and I feel like they lived up to it and made us proud."
Henry said that as of Wednesday afternoon, the team had not officially commenced a search for a new general manager. He also said the team was not yet ready to announce if there would be an interim general manager until the position is filled.
When Epstein was hired on Nov. 25, 2002, he spoke of both short- and long-term goals. With three postseason appearances -- including a World Series championship -- in three years, he obviously couldn't have done much better in the short term. His long-term goal was to revamp the farm system, turning it into a machine the Red Sox could tap into every year while making annual runs at the postseason. That goal is certainly off to a good start, though Epstein won't be around to see the finished product.
"I took very seriously the responsibilities of turning the Red Sox into a championship organization and playing a role in that process," said Epstein. "We did accomplish that. There's a lot more work to be done here. It's sad for me to leave more work to be done. I feel like we're in a very good position for the future with the farm system that these guys have built. I'll watch with admiration, respect and good wishes from afar as they go forward."
Could Epstein, who turns 32 on Dec. 29, ever see himself going full circle and returning to his hometown team?
"Again, the decision right now is that it's the right thing to leave the organization," said Epstein. "It's obviously not a decision that I take lightly. Hopefully my life will be long and take many turns, and I wouldn't rule anything out. But for right now, the difficult decision is to walk away."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.