According to K.C. Johnson of The Chicago Tribune, Adams is still confused over the circumstances that led Bulls general manager Gar Forman to not extend his contract with the team.
"It's still a bit mystifying to me," said Adams, who now serves as an assistant under Brad Stevens. "And I don't understand it. And if the intent was to be hurtful to me and my family, it succeeded."
Adams is touted for his ability to develop young players, and the move to a rebuilding Celtics squad made sense on some level, but it still came as a surprise when the hire was made in the offseason.
Still, Johnson wrote that Adams was very close with superstar point guard Derrick Rose and was anticipating having the opportunity to work with him after he recovered from ACL surgery, which proved not to be the case.
Before joining Chicago, Adams had spent two years as Scott Brooks' lead assistant in Oklahoma City from 2008-10.
Per another piece from Johnson, the decision to not re-sign Adams may have been a public jab at coach Tom Thibodeau, who has clashed with Chicago's front office in the past.
In an address following the decision during the 2013 offseason, Forman repeatedly stressed that he and Thibodeau have a good dynamic and communicate openly, but the Bulls have never given a definitive explanation of why they let go of one of the league's most well-respected assistants.
Forman was thankful to Adams for his work in Chicago, but refused to elaborate on the details of Chicago's personnel matters. He did, however, state that he, not Thibodeau, has final say over assistant coaches.
Now with Boston, Adams has played a major role in the development of young players like Jared Sullinger, Avery Bradley and Jordan Crawford, all of whom are having very solid seasons under the tutelage of Stevens and Adams.
The Bulls have been decimated by injuries and seem in danger of falling out of the Eastern Conference's playoff race.