After 25 years of marriage, the 54-year-old model filed for divorce back in August before calling it off just a month later.
During an interview with The Sunday Times, the 76-year-old action hero discussed the personal upheaval.
"Let's just say that it was a very tumultuous time," Stallone admitted. "There was a reawakening of what was more valuable than anything, which is my love for my family. It takes precedence over my work, and that was a hard lesson to learn."
One of those lessons included an epiphany about his relationship with his children. With Flavin, Stallone shares daughters Sophia, 26, Sistine, 24, and Scarlet, 20 and two sons with his ex-wife Sasha Czack: Sage and Seargeoh, 43. Sage was 36 years old when he died of a heart attack.
"I didn't pay enough attention when they were growing up," he confessed. "I was so career-oriented, and now I go, 'OK, I don't have that much runway up ahead, and I want to start asking them about their lives.'"
This lesson in fatherhood is something that the actor has taken to heart when it comes to his commitment to re-building his relationship with his daughters.
"I ask them about their day, and they started at first a little monosyllabic," he explained. "Then I heard one say, 'I was just thinking about you.' Oh, my God. I've never heard that before in my life. When a daughter knows you care, she's there forever."
In a statement released to TMZ at the time of their divorce filing, Stallone said, "I love my family. We are amicably and privately addressing these personal issues."
The outlet also reported that Flavin was seeking divorce due to the "Rocky" star moving their assets from marital funds.
In their divorce documents, she wrote at the time, "Upon information and belief, the Husband has engaged in the intentional dissipation, depletion and/or waste of marital assets which has had an adverse economic impact on the marital estate. Pursuant to Section 61.075, Florida Statues, equity dictates that the Wife be compensated and made whole by receiving an unequal distribution of the marital assets in her favor. Moreover, the Husband should be enjoined from, selling, transferring, assigning, encumbering, or dissipating any assets during the pendency of proceedings."