The AC Milan striker, 41, believes he “lost his identity” in his only season at the Nou Camp, under Pep Guardiola in 2009-10 but says he regained his swagger once he left and “conquered the world”.
The former Manchester United striker is now in his second spell with AC Milan, but won’t play until the new year following an ACL knee injury.
He told France’s Canal Plus TV: “My worst memory? I think it was Barcelona, but not for football.
“Yes I disappointed myself. I did things differently. I thought twice before acting and I disappointed myself.
“I lost my identity there. Afterwards, I found it again, and that allowed me to conquer the world.”
Ibrahimovic arrived at Barca after three Serie A titles in a row with Inter scoring 22 goals in 46 games.
He told Sky Sports Italia in 2017: “I’d walk into a room and he’d walk out. I’d go to meet him and he’d go somewhere else.
“I understood that there was something beyond football.
“The problem was his, it was he who hadn’t solved the problem with me.
“I remember on my first day, he told me that the Barcelona players didn’t turn up to training in Ferraris or Porsches.
“He’d already judged me then, but if you don’t know a person then you can’t judge them.
“He wasn’t the worst coach I’d worked under, but he was certainly the most immature because a man solves his problems.”