During all of the highs and lows Chelsea have experienced over the last ten years, Branislav Ivanovic has been there and seen it all.
The Serbian made 377 appearances for the Blues and was a key member of the team that won two Premier League titles, three FA Cups, the Champions League and Europa League.
But he proved an unfortunate casualty once Antonio Conte imposed his preferred 3-4-3 system earlier this season and decided that January was the right time to start a new chapter of his career.
Of course, now the 32-year-old is no longer in the bubble that is the Premier League, he is free to open up on some of his experiences on English turf.
As a result, the new Zenit St Petersburg signing has revealed the contrasting styles of the two managers he served at Stamford Bridge that actually guided them to the title.
Ivanovic enjoyed a particularly close relationship with Jose Mourinho during the Portuguese's second spell in charge.
And although his form dipped towards the end of Mourinho's tenure, Ivanovic still rates his old boss.
"They call Mourinho the Special One, and I think he is," Ivanovic told Sport Express, as per ESPN.
"If you win, his trust knows no bounds. He will make you fulfil the potential you were not even aware of.
"Training was unique under Mourinho. He sometimes plays mind games with the press, but when it comes to the most important things, the matches themselves, he is always very serious. If you want to play for Mourinho, you have to follow his demands.
"Mourinho helps to develop the best qualities - professional and personal. You can't be indifferent to him. You either love him or hate him. That's what makes him special. I am glad that I had a chance to work with him."
However, despite Ivanovic's obvious affection for the current Manchester United manager, he has surprisingly revealed that players would probably prefer to spend the rest of their careers with one of Mourinho's predecessors - Carlo Ancelotti.
Ivanovic added: "Ancelotti is very different. If players had a choice, I guess they would prefer to spend their entire career with Carlo.
"He is very calm and takes all the negative aspects of him, allowing the players to be comfortable. The results are equally good with both coaches."
Mourinho's history would suggest Ivanovic might have a point.
So far in his managerial career, the 54-year-old has been unable to stay at one club for more than three seasons and when he does leave, it is usually in very acrimonious circumstances.
But that is the least of Ivanovic's problems now and he is all set to start his Russian adventure with Zenit.
The full-back admitted he could have followed Oscar and John Obi Mikel to China last month but wanted to keep playing at 'a decent' level.
"I asked [the club] to release me if I received a suitable offer. Chelsea agreed, and I am very happy with that," Ivanovic continued.
"There was an option to go to China, but I want to play at a decent level and continue my development. That's why I chose Zenit."