Pogba played a key role in Juventus' title wins from 2012-13 to 2015-16
The 29-year-old has rejoined Juventus after leaving United following his deal with the Old Trafford club expiring.
"I'm happy with the choices I've made in my life," he said.
"Sometimes you make choices that don't go your way but I'm happy with the years in Manchester. I grew up, I learned, I became a man."
Pogba, who came through United's academy, left the club in 2012 to join Juventus and won the Serie A title four times with them before moving to back to the Old Trafford side for a then world-record £89m transfer in 2016.
He won the EFL Cup and Europa League with United in his first season back at the club but they were the only trophies he won in his second spell with them.
He played for managers Jose Mourinho, Ole Gunnar Solskjaer, Michael Carrick and Ralf Rangnick following his return to United and failed to produce his best form on a consistent basis under each of them.
However, Pogba, who has 91 international caps, was influential as France won the World Cup in Russia in 2018.
"Changing [Manchester United] coach every year is hard - this was a difficult aspect for me," said Pogba. "Then there were a few injuries, but I think it was also a mental thing - playing and not playing makes you lose pace.
"There is a bit of everything: coach, team, position. All this has blocked me a bit.
"Now, however, I have left and you will see another Paul. I can do better than in recent years."
Pogba has signed a four-year contract with Juventus, who finished fourth in Serie A last season.
He added: "I am happy to go home, this is how I feel here. This is something more than a dream. I am very happy.
"There were other teams interested, but my heart chose Juventus. I was fine here before and I'm fine now, I just want to do well.
"I can't wait to start and help the team. I hope to do better than last time."
-- Courtesy of BBC Sport