More than money, offensive weapons or warm weather, Tom Brady may have just been chasing happiness and appreciation — two things he couldn’t get from Bill Belichick.

Brady shocked most of the NFL last week when he announced he was leaving the Patriots and later signed with the Buccaneers. He left a franchise defined by success over his 20-year run in New England for one that has lost more games in the last six-plus seasons than Brady has in his entire career.

But there was a reason Brady was a free agent for the first time and a reason why the six Super Bowls weren’t enough to keep him a Patriot — a growing rift between him and his head coach, according to a new ESPN story.

“To many of the executives who did due diligence [on Brady ahead of free agency], Brady seemed so driven by an animus toward Belichick that they couldn’t tell if he actually wanted a fresh start or if he just needed leverage to force Kraft to step in,” ESPN’s Seth Wickersham wrote in a story published Sunday.

The 42-year-old Brady often made it known that he wanted to play into his mid-40s, but Belichick and the Patriots made it equally known they were not willing to give him that kind of commitment. Instead they went year-to-year, which caused a growing frustration.

A meeting between Brady and Belichick in the fall of 2017 resulted in a “blowup,” per an ESPN source. Last August, before Brady and the Patriots agreed to a two-year contract “extension” — which would raise his salary in 2019 but automatically void on the final day of the 2019 league year, making him a free agent — the quarterback was ready to walk out of training camp, according to NBC Sports Boston.

“[Brady] wanted what everyone wants from an employer: to feel valued and to love work,” Wickersham wrote. “They seemed like two reasonable asks — until Brady realized that in New England, under Bill Belichick, he might be asking the impossible.”

Before Brady became a free agent this month, he and Belichick had a phone call that did not go well, according to multiple reports at the time. No extension came out of it and Brady’s camp viewed it “as further proof that the team wanted him only under its rigid terms and the team exploiting the chance to leak that it had an offer for him and that the ball was in Brady’s court,” Wickersham reported.

“For all of Belichick’s greatness, and for all of the praise that he had thrown on Brady in public and all of the hard coaching he had dished in private, the relationship had run its course,” he wrote.

Patriots owner Robert Kraft seemed to say as much this week without naming Belichick, when he told NFL Network: “Think about loving your wife and for whatever reason, there’s something — her father or mother – that makes life impossible for you and you have to move on but you don’t want to.”

The Buccaneers and Chargers were known suitors of Brady, but there were also plenty of other teams that were linked to him on the rumor mill, including the 49ers. According to ESPN, that was no mistake. Brady grew up just outside of San Francisco, in San Mateo, Calif., and idolized 49ers quarterback Joe Montana.

“Brady made it clear through various channels that the team of his childhood would be the team of his future, if the 49ers wanted,” Wickersham wrote.

Instead, the 49ers remained committed to Brady’s one-time heir apparent, Jimmy Garoppolo. But Brady still pulled a Montana, leaving his longtime team to join another in the final years of his career.