The 32-year-old opening batsman announced he was standing down on Monday after a record 59 tests in charge with Joe Root favourite to succeed him in the role.
Under Cook's tenure England have faltered, drawing two of their last three series and suffering a 4-0 drubbing in India.
"After four or five years of doing it things have just changed and ultimately, during the last year, the team have played some good cricket without pushing on," Cook, who won 24 and lost 22 of his tests in charge, told reporters on the Lord's outfield on Tuesday.
"As captain you are part of that and I think it will be good for the team to have a new voice driving things on in a slightly different way.
"There are huge talents in that dressing room and I hope to be still part of it and be able to lead in a slightly different way. I'm still excited by that."
Cook, whose highlights included two Ashes victories at home in 2013 and 2015 and a first away series victory in India for 28 years in 2012, said it had been a "huge honour" to captain his country for 4-1/2 years.
However, he was confident he had made the right decision.
"It was a hard decision because of how much I've loved being captain," Cook, England's leading scorer in tests with 11,057 runs, including nearly 5,000 as captain, said.
"I've absolutely loved leading the players in the dressing room, it's been fantastic, so to give that away is hard, But ultimately it's the right decision because it's a job that you can't do anything less than 100 percent.
"Unfortunately, as stubborn as I am, I know that I couldn't do it any more like that and it would not be fair to myself or the team to continue at 95 percent."
Cook was in charge through some turbulent times, including a 5-0 Ashes whitewash in Australia in 2013-14 after which England and Wales Cricket Board (ECB) chiefs axed maverick batsman Kevin Pietersen from the team.
Speaking about Cook in his book Pietersen labelled him as "a company man".
While Cook said there had been "dark moments" during his tenure, not least the Pietersen episode, he said he had no regrets as he hands over the reins.
"I've always tried to do what I thought was best for English cricket," he said.
If Root, as expected, does replace him, he will do so with a ringing endorsement from Cook. "He would do a very good job. He obviously has something about him to bat the way he does," the mild-mannered Cook said.
"He has a huge amount of respect in the dressing room."
First Published: February 7, 2017, 11:03 PM IST