His decision, he says, was in some part a consequence of the clash of ideology, the Liverpool approach offering greater professional satisfaction than the PSG mega cash injection.
"They are two different styles, the influx of money or building player-by-player to fill out the squad. The Paris model was very business minded in that sense," said Sakho.
"I have come here to a club that functions with a family mentality. That is what suits me and I feel already that we have everybody in the family group, heading towards the same goal.
"Of course it was a big step for me to leave. I'd been with Paris St-Germain from the age of 12 but there comes a time in every player's life when you have to make some career choices. I had achieved everything I had wanted to do with Paris St-Germain, we had won the title, and I made the decision a while ago that I wanted to take on something else.
"I knew I wanted to experience a different culture and learn new things and when Liverpool came in for me I was easily convinced. I was happy to leave in the end.
"The (Paris) club does have a big project underway and that reflects their ambition, but my situation was based more on my desire to genuinely compete and that is something I know I will have at Liverpool.
"It was an impulse to leave Paris St-Germain. There are so many new players coming into the club but they didn't push me out at all. It was all about me wanting to go out and genuinely compete.
"There are a lot of very good players at Liverpool and the club has shown great ambition for this season. They have big ambitions for the Premier League and obviously the clear objective of qualifying for the Champions League.
"That appealed to me, as did the chance to move to another country and to another culture. I think I will be suited to the English style of play too. As I said, I felt I had done it all with Paris and that it was time for me to turn the page."
Sakho's debut at the Liberty Stadium is best described as erratic. First night nerves and not having played since the end of last season were a factor, but he is sure his attributes are suited to England.
Such is his strength, he managed to break one of the club's exercise machines in his first week of training, the mechanics buckling under his physicality.
"Yes this is true," he said. "One of the machines did break. Something went wrong with it, so they had to fix it not reinforce it. I do want to continue developing my strength as it is a key part of my game. I am a defender and I need to use that but I need to fill out more and bulk up to progress.
"The Premier League demands a great deal of rigour and concentration from all players and that can only help me develop as a person and as a player."
It will not just be the running machine in need of repair. Sakho does not arrive brimming with confidence. His career stalled in France after a series of high profile mistakes, the first shortly after Ancelotti took over in Paris.
The captaincy was taken off him and the steady stream of expensive replacements triggered the first wave of speculation he would be sold, accentuated when Sakho was left out of the most high profile fixtures.
Brendan Rodgers believes his most astute signings are players of proven pedigree with something to prove.
Sakho has that and says his decision to leave Paris, and choice of destination, reveals everything about his motivation.
"I have been brought here to fill a need of the club," he said.
"The most important thing is to come here and wear the shirt with pride and to take the club as high as possible. This is a new page in the history of Liverpool and for me I want to make my mark on that page. I came here for the football, not the money. I had a year left on my contract and in four months I could have gone on a Bosman.
"I put football and the chance to move here above personal gain."