The Pole left Juve a year before his contract was due to expire and subsequently retired before the Barca opportunity opened up.
He told Sport: "It was an incredible privilege to represent Juventus. They are an incredible club with a fantastic fan base. But when I decided to leave them, I couldn't motivate myself with a new adventure at a 'normal' club. It had to be a bigger challenge than Juventus, and there aren't many.
"That's why I didn't want to pretend that I could motivate myself anywhere else and I preferred to go home and be with my family. And just when I was comfortable there, Barça came along. At first I asked for time to think about it, but the first question is: 'Is this the challenge you want to accept?' And in my head I knew I had to say yes.
"To come here and do something good for this club and be at the level it requires is something very special."
On Juve, Szczesny continued: "The club told me that I was too expensive for the club because they were going through financial problems and that they would like to find a solution. And out of respect for Juve, we found a solution. And that's how it ended. I could have stayed and collected my year, but I believe in personal relationships and the club respected me a lot.
"And I also believe in karma. It was instant. Because now I will be in the last year of my career at Barça, the biggest challenge I have ever taken on. The world paid me back for being respectful to Juventus."