Murray has steadily improved year on year at Wimbledon and as he said on Sunday night, his victory has been a great example of "perseverance".
For many years he struggled to get past the semi-final stage, suffering an especially tough loss to Andy Roddick in 2009, a match where he went in as the favourite. And then in 2010 and 2011 he was simply outplayed by Rafael Nadal in the last four.
He finally managed to get through to the final for the first time last year, but lost in four sets to Roger Federer, and McEnroe believes that his Olympic success a month later played a crucial part in his coming-of-age as a Grand Slam champion.
"It's been a long time coming," McEnroe told the BBV.
"He was getting closer and, to me, the Olympics was the big difference. He had to get back off the mat after losing to Federer last year and that forced him to get back on the court quicker. All of a sudden the crowd really got behind him, realised they could make a difference and they did."
Murray has said that winning the US Open was a huge relief and McEnroe believes that experience also made a big difference when it came to the pressure cooker of Wimbledon.
"He won the US Open, so that took a little bit of pressure off," he added.
"The draw opened up and it was like 'he's got to get at least to the final'. He did that and then he was able to play up to his ability."