CHICAGO -- For all the talk about bad blood between Jon Lester and the Boston Red Sox stemming from a lowball offer prior to spring training, what really appears to have greased the wheels for Lester's moving on from Boston to the north side of Chicago was the July trade to the Oakland Athletics.

"I think if we finish up [the season] in Boston and you get down to this decision, I think it would be a lot harder," Lester said while draped in Cubbie pinstripes and donning his new No. 34. "Not to say it wasn't hard as it was, but I feel like that broke that barrier of, "I wonder if I can play for another team." And I think we answered those questions."

Lester added that he understood what the Red Sox were doing at the time. It made plenty of sense with them out of the playoff race to move a soon-to-be free agent and try to position themselves for 2015 and beyond while still holding out hope to re-sign Lester in the offseason. He was adamant that the trade didn't foster any ill-will for him toward the Red Sox organization.

"It didn't piss me off," Lester said. "Obviously, it's difficult in the middle of the season to pack everything up, especially when you have two young kids, and move across the country. I think it helped prepare me for the situation, as far as preparing myself to pitch in another uniform. If it didn't work out to where I went back to Boston, I know that I can perform in another uniform, in another city, for another organization. I know that seems stupid, it's done every day, but for me it was very difficult. When you're drafted by these guys and you're groomed by these guys for 12 years, to put on a different uniform, that was a little hard."

Red Sox principal owner John W. Henry was pretty open that while trying to lure Lester back to town, he kept pushing the idea of finishing off his legacy in Boston. Having already won two championships with the Red Sox, the possibility of finishing off his career at Fenway and potentially being part of a dynasty had to tug at Lester's heart. Lester admitted that everything weighed into his decision-making, but in his mind, the legacy aspect had already lost some weight.

"In the end, that's important, but it's really not," Lester said. "Kind of the legacy got broken up a little bit when I went to Oakland. I understood what [Henry] was saying about that, about coming back and finishing it. And that's something that we weighed very heavily at the end. But just the idea of coming [to Chicago] and breaking their curse -- like I said earlier, I didn't get to be a part of the '04 [Red Sox championship] -- so I thought this was just something that kept pulling at us."

Lester was complimentary of Henry and said the final pitch Henry gave when he came to Lester's home in Atlanta will always be something that sticks with him.

"It was very humbling," Lester said. "He and his wife flew down and we just sat very casually around the living room and just talked. That meant a lot to me, I know it meant a lot to my wife for them to come down and do that. And in the end, that was just one more thing that made it that much more difficult for us.

"But one thing that I'll always take, and he said it to me a couple times, that I do respect and I'm truly honored that he said it to me, he said, 'No matter what your decision is, we're happy for you and you'll always be a Red Sox.' That meant a lot to me and my family that he did that."

Lester said that money was not discussed during the meeting, which he felt was very important and added to how much the sit-down meant to him.

"That meeting is near and dear to my heart. I could tell it took a lot for him to say the things he wanted to say," Lester added. "I will always remember and I will always cherish that meeting; it was a great meeting. Both on a professional level as far as Red Sox negotiations and on a personal level, it was just great."

While the trade to Oakland clearly made things a bit easier for Lester to choose the Cubs over the city where he'd spent nearly his entire career, one thing he says didn't weigh into his decision was the apparent lowball offer of four years, $70 million that the Red Sox made prior to the 2014 season.

"We're all grown men, I understand the business side of baseball," Lester said. "I know what they were doing, I know what they were trying to do. If you let feelings get in the way of this, then you're making the decision for a wrong reason. If I make a decision based on an offer they made in spring training, then I'm not setting myself up for the next six years to be happy.

"One thing that we tried to do is let bygones be bygones. When they walked into our house, I said, 'Listen guys, we're starting all over. Whatever happened during the season, happened during the season; we're not looking at that, we're looking at now.' I think that helped them, because I think that still tugged at them."

With all that said, it's hard not to feel that the Red Sox didn't capitalize on their longstanding relationship with Lester and an exclusive negotiating window with him last season. Add in the fact that he stated a desire to remain with the club, potentially at a discount, in January and it feels all the more like a missed opportunity.

"I don't know if they didn't take full advantage," Lester said. "You guys [in the media] kind of hear bits and pieces of the conversation. I know everything gets focused on their first offer, but by no means was their first offer an ending point of conversations. We continued to have conversations, I talked to [general manager] Ben [Cherington], I talked to John [Henry]. The conversations were there, the effort was there, we just didn't make any headway before Opening Day. I think things are getting kind of blown out because of the second-guessing. You can always second-guess when it doesn't work out, but I think that's hard. It puts everyone in an unfair position because you can always point fingers."

One aspect that did weigh quite heavily with Lester was the trust he had built with Cubs executives Theo Epstein and Jed Hoyer, who built a strong relationship with pitcher while all were in Boston. Both Lester and Epstein used the word "belief" multiple times when talking about the pitcher's choice to come to a team that has finished at or near the bottom of its division for five straight years now.

"We knew early on it would be about belief if we were going to get him," Epstein said. "We didn't have all the evidence, tangibly, that you'd normally want to present a free agent. If he was going to come here, it was going to be because he believed in our future and he believed he wanted to be a part of doing something special. So we focused on that."

Lester said the Cubs presented him with as much information about the team as possible and really sold him on the fact that despite the recent lack of wins, the organization is on the rise and good things were coming fast. It clearly took a lot of trust on Lester's part to make that decision, but Lester had built it up with Epstein over the years and felt comfortable enough taking the leap.

"When you know somebody, you can tell if they're lying to you," Lester said. "Obviously, I felt that wasn't the case. They really sold me on the facts of their plan and what they thought this team can do in the future. That was huge for me."

In the end, relationships seemed to be the theme of this free-agent courtship. Epstein said he didn't think much about competing directly with Boston for a free agent, but he did admit it was difficult seeing a disappointed Cherington and manager John Farrell the morning after Lester's decision was announced. For Lester, the toughest part was saying goodbye to the Red Sox and the teammates he'd grown so fond of over the years.

"I wanted to call those guys that meant the most to me while I was there; I tried to do it before it came out, which was kind of hard," Lester said, singling out Dustin Pedroia as a former teammate whom it was particularly difficult to tell he wouldn't be returning to Boston. "That's what makes Pedey so great -- he can call you one minute and cuss you out for not coming back and you call him a few hours later and you're shedding tears with him. Those guys I'll love and consider my brothers until I'm dead. That one was probably the most difficult, and probably second was calling Ben [Cherington]."

The decision to leave Boston clearly wasn't an easy one for Lester. He repeatedly brought up the fact that his heart would always be in Boston, but the lure of a new challenge with a group he trusts and believes has built something real in Chicago was just too strong.

"I've had a lot of great memories [in Boston], got in a lot of great relationships there with people, and it made this decision very, very difficult," Lester said. "In the end, we just felt like this would be a new and exciting chapter for us and something that we wanted to try to conquer. That outweighed the Boston decision."