The Frenchman left Juve after guiding them back into Serie A following their Calciopoli demotion.
Deschamps told Tuttosport: "At the time, it seemed like the right decision to me. Instead it was an error that was all my own doing.
"With the passing of time I have realised that people within football did not understand the reasons behind that decision. I'll give you an example: Last summer I was contacted by Liverpool and the first thing that my interlocutors asked me during the meeting was: 'Why did you leave Juve?'
"The club and I had different visions of the future and I must say that even those people close to me, like my agent, didn't advise me well.
"In practice nothing could reset the fracture. The fact is we were coming of a year that was difficult psychologically, one in which we found ourselves in cities and stadiums that Juve had never visited before.
"Every game was a battle. We really consumed a lot of energy and I knew that the expectations the following year would be even higher. But one couldn't pretend to win the Scudetto right away. We needed to go forward by degrees, to rebuild. My position at the time was clear: better to sign three very strong players a year rather than six or seven of average worth. To be at the height of their past and the expectations that surround the club, Juve need a continuous turnover of champions.
"Sure, quality has its price, but that year in Serie A we managed to launch young players like Claudio Marchisio and Paolo De Ceglie, so we could have concentrated on a few reinforcements of a high level."