The day Slater thought he would never play 300 games

Only once during these kitchen chats did the mood darken. The place I asked Slater to revisit was still painful and, as he recited the details, tears welled in his eyes for the only time in months of usually fond reminiscence.

Slater was recalling the time in March, 2016 he went to see a surgeon in Sydney to get a second opinion on a reconstructed shoulder that would not heal. How, upon his return to Melbourne, he retrieved a voice message on his phone while driving home from the airport.

The news was devastating. The initial surgery had failed. He had wasted months working to rehabilitate the joint. More surgery was required. Slater pulled over to the side of the road and broke down.

It was the first time in a career punctuated by extraordinary highlights and a few setbacks that Slater experienced footballing mortality. The moment that playing again, let alone reaching this round's 300-game NRL milestone, seemed beyond him.

That Slater will play his 300th having been in 2017 part of a winning Queensland State of Origin team, the Clive Churchill Medallist in a Storm premiership-winning side and a member of Australia's triumphant World Cup squad was unthinkable, even unfeasible.

Not just when he received the grim diagnosis, but almost a year later. Throughout the summer of 2016-17, there were several times where the self-doubts surfaced, and Slater's return seemed uncertain.

While Slater would probably not see it this way, a psychological barrier had been erected. The subconscious fear of another this time career-ending injury stopped him fully extending the shoulder at training. Unusually for a man who hates missing a second of a game, he seemed relieved rather than let down when he told me he was not playing in the first two games of the 2017 season.

Although Slater did not reveal his emotions readily, it struck me that during this summer of uncertainty the great fullback was, for the first time, genuinely scared about what might happen on the field. For a man to whom the game came so naturally, this was clearly a confronting experience.

Throughout our collaboration I had asked Slater in dozens of different ways how he found the courage to stand under high balls with 120kg assassins charging toward him with murderous intent in their eyes.

I tried to relay my own feelings of vicarious terror when standing near the in-goal area during Storm drills years ago where Slater and his wingers would fetch bomb after bomb, while muscular teammates, particularly that crazed human cannonball Jeff Lima, would smack into them with intent. And this wasn't even close to full contact.

Slater would always answer with a technical tip about turning the body in the air or jumping from the correct foot. He did not understand my question because if he had experienced the kind of debilitating fear I imagined, he would have been in the grandstand with me.

So where Slater's incredible return last year was considered a feat of medical rehabilitation and further testament to his unquestioned ability, it was also a demonstration of the courage and willpower required to dominate a bricklayers' game with a trackwork rider's body. Perhaps Slater's greatest display of courage because, for once, he was well aware of the demons he was confronting.

That said, one of the game's bravest and most breathtaking players might be its most down to earth. Slater watched the first two Storm games of 2017 on the couch wearing tracky dacks beneath a rug with daughter Tyla and son Jake – his perfect night. He merely starred in most of the rest.

Some wondered why Slater seemed so emotional upon mentioning Nicole – his "darl" – during the grand final presentations last year. But this was completely understandable to anyone who had seen the love and support they had given each other through some tough times, not just Slater's battle to get back on the field.

Equally, the importance of Slater's "Storm Family" to his success and longevity is more than just newspaper story cliché, but palpable when you see the practical ways those who join the NRL's most successful club support each other on a daily basis.

It will seem strange to celebrate a milestone without a close family member, Cooper Cronk. Though Slater is closer to Cameron Smith because they have young children, the so-called Big Three (a title they all loathe because of its selfish connotations), had a way of finding each other in the biggest moments. With the ball and, when the hooter sounded, in the post-game celebration where they would exchange a warm embrace or a knowing glance.

Slater and Smith will find each other after the game. They will celebrate what they have achieved together in those 300 NRL games and, knowing how close Slater came to the brink, the sheer joy of just being out there.

Billy Slater - Autobiography (with Richard Hinds). Ebury Press. Available at all good book stores.