Only three weeks ago, Cook was assailed by a chorus of disapproval – led by several former England captains, calling for his resignation. Less than two months ago, as revealed at The Oval on Friday by England and Wales Cricket Board managing director Paul Downton and by Cook's own admission, as he reflected after winning by an innings and 244 runs, he was on the brink of walking away.
But, after speaking to his wife, as England descended to series defeat against Sri Lanka at Headingley in mid-June, Cook decided he would not, after all, go quietly.
More distress followed with a landslide defeat at Lord's and a 1-0 deficit in this series, while his quest for a 26th Test century has extended to 31 innings and will now not end until the Caribbean next April at the earliest.
Cook has, however, returned to relative form – and most importantly has led England to three successive victories, the last two by huge margins, to prevail 3-1 on the back of James Anderson and Stuart Broad's wickets and reliable batting from Joe Root and others.
Recalling his evening of doubt in Leeds, he explained what helped him stick to his guns.
"(It was) the support I had from my wife," Cook said.
"You can bare your soul quite often to Alice, and she's very good at getting me back on the straight and narrow.
"But that fourth night was a tough moment. We'd let a winning position slip and Lord's was very tough as well, losing there in conditions very suited to us and winning the toss for a big advantage.
"But I'm quite stubborn; I believe in my ability, and I'm quite a resilient guy – and that was when I needed it most."
The culmination is a much-needed series victory for Cook and returning coach Peter Moores' new era, which was concluded as Root completed an unbeaten 149 on the third day and final day of the fifth Test and then Chris Jordan's career-best four for for 18 helped hustle hapless India out for only 94.
"I'm glad I stuck through the tough times," said Cook.
"That's what sport does, tests your character, and to bounce back as a team is a testament to us.
"I don't play this game to prove people right or wrong. I never have. I do it to try to win games of cricket for England, and do my best at all times.
"So I'm not going to be sitting here gloating, that's not who I am.
"I'm here because I believe that I am the right man to try to lead this team forward.
"I'm very, very privileged to be England captain. It's a great job to have – even through the tough times.
"You walk out every morning, and you have the name - 'here comes the England captain'.
"When that's your name, you do it for such a short period of time in your life, you have to hold on to it as long as you can and give everything."
He never lost faith, but is still surprised at such a comprehensive turnaround.
"I remember saying, when we were 1-0 down, that I still thought we were going to win the series," Cook said. "I had a lot of confidence in the talent and amount of skill we had in the dressing-room.
"I didn't think we'd win quite so emphatically, as we have done."