England opener Alastair Cook says he decided to call it quits since he had lost the mental edge with which he managed all his tasks with ease.
The fifth and final Test begins at the Oval on Friday, and with the hosts already 3-1 up, it will be the last international match of Cook's 12-year-long career.
"I've always had that mental edge, I have always been mentally incredibly tough and had that edge to everything I have done but that edge had kind of gone. The thing I had found easy before was not quite there and to me that was the biggest thing," Cook said.
Asked about the decision to call time on his long career, Cook replied, "It's hard to put into words but there have been signs in my mind over the last six months. I told Joe Root before the game (in Southampton) and then Trevor Bayliss during the game. In this day and age it's very difficult to keep anything quiet. If it were 2-2 I'd have kept my mouth shut."
"When you get asked questions (from the media) it's hard to constantly lie. I've been pretty good at it! But there's certain stuff when you're asked questions you know you're not being true to yourself. There might be a bit of fuss about it and if it were 2-2 I'd have kept my mouth shut."
"At Southampton, I was a couple of beers in which I needed to be otherwise I would have cried more than I actually did. I managed to hold it together. At the end of the game I just said 'this might be good news for some and sad for others but it's time. I've done my bit and if picked the next game will be my last one.' That's kind of all I said. There was a bit of silence, Moeen Ali said something, we all laughed and everyone got on with it. We had a nice evening in the changing room.
Cook also led England in 59 Tests and 92 ODIs. He termed the Ashes win in Australia (under Andrew Strauss) in 2010-11 and the 2-1 series' win in India under his leadership (in 2012) as the highlights of his record-breaking career.