Every time he hears it, John McEnroe takes a sense of pride in its meaning. 

He smiles as he repeats it, reflecting on all that it represents in his life. 

“I married a bad boy who turned into a good man.” 

The line was initially delivered by McEnroe’s wife, Patty Smyth, in the upcoming documentary “McEnroe”, which will be released on Showtime on Friday. Those words encompass his public — and private — journey from a polarizing American star to his current place in life, far from his on-court outbursts. 

That evolution – from a “bad boy” to a “good man” – is central to the film’s inquisition. The persona fans, and detractors, came to know – one of tantrums, vulgarity, rage – was a product of something much deeper. Intense pressure to be the best, imposed on him by himself and by his at-times overbearing father John Sr., mounted on McEnroe. 

The character McEnroe presented in public bore all that. 

“Instead of expressing vulnerability, and almost, you want to cry, I turned it into anger, to hide that,” McEnroe told The Post. “So it comes off differently than what I was actually feeling at the time. I’m not justifying it, but that’s just how I dealt with it.”

Perhaps McEnroe’s greatest evolution has been his relationship with that intensity that surrounded his life. In marriage – he’s been married to Patty Smyth for 25 years – and fatherhood of five children (three of whom were with his first wife, Tatum O’Neal, and the other two of whom are with Patty Smyth), McEnroe has developed a new appreciation for those emotions. 

Pressure, intensity, vulnerability, even fear. What McEnroe once buried, he now embraces.

“I think people lose sight of, I think if you can explain to people and show people that listen, a lot of it is great,” McEnroe said. “Being able to play tennis for a livelihood, my perspective has changed quite a bit. You go from that glass half empty, for a period of time, then you’re like ‘Whoa, maybe this wasn’t that bad after all. This is pretty amazing.’ I feel good that I’ve been able to, each year of my life, try to get a better and better perspective and feel better and better about where I am as a person.”

The change has been noticeable for McEnroe, and his relationships with those around him. It’s impacted his mindset as a tennis analyst, and how he views current players’ behavior. It’s brought greater peace to his life, and inspired others to do so as well. 

McEnroe, now 63, has watched the sports landscape change around him. He’s also seen other things stay the same, consistent from when he played. 

In this stage of his life, finding that balance for others, as he did himself, helps offer a new endeavor. 

“I think what it shows, because certainly the mental aspect of athletes and sports has come to the forefront a lot more with Naomi Osaka, Simone Biles, and others,” McEnroe said. “But it’s not something that hasn’t been there in a long time. It used to be like growing up, guys don’t cry. Suck it up.

“You hurt something – take two aspirin and get back out there. So a lot of things are changing in society. Mostly for the better, but some necessarily, the pendulum has gone too far the other way. 

“So I think it’ll be interesting, for people to look at this documentary, because obviously I’m not in my 20’s anymore, and sort of compare, in a way. Where we were, that’s sort of what I did in my own documentary. Where was I then, and where am I now? And in similar fashion, sort of look at the world of sports in that way. And sort of see what we’ve done that’s improved it, and what things we need to improve and back off on. I think that part of it, to me, interests me.”