Beams, a Collingwood premiership player and their best-and-fairest winner two years ago, was the subject of one of the biggest deals in this month's trade period.
The onballer had a year left on his contract, but asked for a move north because his father Phillip has been ill this year with cancer.
Brisbane failed to meet an initial deadline set by the Magpies before the deal eventually went through.
"It hasn't been a decision I've made in the space of two weeks," Beams said.
"It's something I've thought about a lot through the year.
"To me, my family is everything.
"My decision was based purely around that and what was going to best for me, my missus and the rest of my family."
Beams admits it was a stressful period, but he was always confident the deal would go through.
He was holidaying in New York with now-former Collingwood team-mates when the trade was confirmed.
"Obviously there was a bit of a process - [I] felt like the meat [in] the sandwich at times - but I knew that when I made the decision.
"It was a relief."
Beams says Magpies president Eddie McGuire and coach Nathan Buckley were understanding about why he wanted to leave.
He revealed he also spoke to Buckley before making the controversial decision to miss the club's best-and-fairest function.
A Melbourne newspaper published a photo of Beams drinking at a pub on the night of the function.
"I wasn't surprised, because I was there," Beams said of being at the pub.
"That (the photo) didn't worry me one bit.
"I would have felt too uncomfortable (attending the function).
"Bucks was fine with it."