The 52-year-old lost his job after 13 months at the South Coast club in August 2010 just days after he had guided them to a 4-0 League One win at Bristol Rovers.
A little more than three months later, he was back in work after Magpies owner Mike Ashley handed him his big chance, and although it has been eventful both on and off the pitch since, Pardew celebrated three years at the helm earlier this week.
He still believes his departure from Southampton was unjust, but accepts the experience was all part of the vagaries of his chosen career.
Pardew said: "I always felt that it wasn't so much a footballing decision because I don't think anybody could argue - and certainly the fans there were brilliant for me and the players were all with me, so I had no issues with that, really.
"It was a decision that was made above me and there was nothing I could do about it.
"But I never lost my confidence over that. That's managerial careers, we are very vulnerable.
"I have been here three years. I have been vulnerable from day one and I am still vulnerable today."
Pardew certainly has been vulnerable, no more so than as last season drew to a close in most unsatisfactory fashion with the club fighting for Barclays Premier League survival 12 months after finishing in fifth place.
But a run of five league wins in six, the last of them ending a 41-year wait for a win at Manchester United, has seen his stock rise sharply once again.
The victory at Old Trafford came just three days after a disappointing 3-0 defeat at Swansea, and those two games represent in microcosm Newcastle's existence, shifting quickly from disaster to triumph and back again with little else in between.
Pardew said with a smile: "I have tried to be consistent with my message to the players, and sometimes it's difficult to do that when you have had a really tough day.
"We have had a lot tougher days than Swansea here and you have to endure those, but it always makes up for it when you get fantastic results.
"If someone had said to me, 'You will be Newcastle manager and you will beat Manchester United 3-0 at home and you will win at Old Trafford 1-0 and deserve to win', I would have taken that and lost all the others, probably.
"Joking aside, it's something you have to get used to because it's a big city and it's a city that lives and breathes the game, so therefore it is all around you and you have to get used to that."
A fourth successive home win would cement the Magpies' place in the upper reaches of the league table, although Pardew admits it would be that little bit more special for him to get the better of the Saints.
However, he will be equally pleased to see some of the men who worked under him during his brief reign, and who have gone on to bigger things since.
He said: "I felt it was an injustice to lose my job there, but I'm not the first manager to say that.
"But I am certainly looking forward to seeing some of my old players, who have done absolutely brilliantly - [Jose] Fonte, [Rickie] Lambert, [Adam] Lallana, [Morgan] Schneiderlin were all there in the first division with me and I loved working with them.
"I am looking forward to seeing them. I am over the moon that they have got international recognition, Lambert and Lallana.
"That side of it, I look forward to seeing - but certainly on a personal level, it's a game I really want to win."