The Scot admits that he never thought of turning down Manchester United offer.
Premier League: David Moyes says Everton 'a great part of my life'
He said: "Have you nothing to do today?"
Everton officials had insisted Moyes would not talk about his decision to take over United, but the conversation was inevitably pulled in that direction.
"I'm disappointed to be leaving such a great club," he said. "The club has been such a great part of my life."
But when asked if he had considered turning down United's approach, Moyes said simply: "I have to be honest and say no."
Moyes rejected the notion that the deal had been done weeks ago and said he had been planning for next season.
"My contract was running out but if you had pushed me, I would have said I would stay," he said.
"Everything is in place for next season, pre-season has been arranged and the chairman knew what I wanted to do."
Only once did Moyes speak specifically about the man he is about to replace, underlining what a loss Sir Alex Ferguson is going to be to the British game.
"I don't think anybody thought the day would come when Sir Alex Ferguson retired," Moyes said.
"We all thought he was superhuman. The respect for him within the game is beyond any words I can use."
Moyes said he would understand if some Everton fans were upset at the manner of his departure.
However, he wants to see the job through and intends to stand in exactly the same place in his dugout on Sunday for the encounter with West Ham United.
"Hopefully, on Sunday, the fans will react in the same way they did when I first walked through the door," Moyes said.
"You can never tell with football fans. They support their team, and I would understand it if they weren't happy. But I will be standing in the same position as I always have done, trying to see if we can take this outside chance of getting into Europe."
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