My entire adult life supporting Celtic has been defined by the Lisbon Lions and Jock Stein.

Throughout all the triumphs and agonies and all the blessings bestowed by this club those men and their manager – our manager - have been there, a constant reminder of how our finest moment was achieved through glorious simplicity and honesty.

I wasn’t old enough to experience the actual joy of Lisbon but that hardly seemed to matter. Those who were there and who bore witness to the greatness of those players bequeathed their memories to the next generation in the years that followed. Even during periods of suffering it was a consolation to know that, for a few years, Celtic had once been the best football team in the world. 

On Saturday against Dundee United, I watched as Jim Craig took his place in the director’s box. I caught myself fervently hoping that his presence in the boardroom for our home games wasn’t just a one-off and that a seat would always be provided for him. And for each of the three other Lions who are still with us.

I also caught myself looking closely at him for any signs of infirmity, as you do when you meet an elderly relative whom you haven’t seen for a while. I’m glad to report that Jim still looks in rude health, dapper in his suit and overcoat; still sharp and keen.

And then you start thinking of his three surviving Lisbon team-mates John Clark, Willie Wallace and Bobby Lennox. How were they all doing? Are any of them struggling? Are they all being looked after?

READ MORE: Lisbon Lion John Clark relives Celtic's greatest glory 55 years on

Part of the greatness of these men lies in their deeds in the decades after Lisbon. The way they have all conducted themselves in those years is a testament to their qualities as men. They were still young when Lisbon happened and still had other feats to achieve. And I always sensed that, in the moment, they might not have fully appreciated what their achievement meant to Celtic supporters and to the entire nation of Scotland.

I think it was only after they had begun the process of retiring from the professional game that they began to grasp fully what their achievement meant to the rest of us. How many supporters’ functions have they all attended in the years that followed? Thousands? More than that?

I can think of many occasions where a supporters’ function I was attending was graced by the presence of at least one of them. At these events the warmth and affection – love even – with which they were greeted remained undimmed through the years. Their presence was appreciated by the youngest generation of Celtic supporters as much as by their parents and grandparents.

As football began to reward players with life-changing wages they inevitably began to disengage from the supporters and to remove themselves from the places they frequented. For most of them, these supporters who idolised them would be supplanted by another club’s fans in a year or two.

Celtic Way:

Celtic weren’t immune from this disconnection either. Certainly, many of our great former players in recent years such as Moussa Dembele and Chris Sutton and Henrik Larsson still seem to retain a place in their hearts for Celtic. But those days when Celtic’s players would be expected routinely to attend a supporters club’s event are long gone. Yet, this was once considered to be a weekly norm for the Celtic players.

Once, you could walk up to Parkhead on a midweek lunchtime and have pictures taken with the players when they returned from training at Barrowfield. My favourite image of the Lisbon Lions era is of several of the greatest players in the world walking back along London Road after training accompanied by that ‘wee Glasgow wummin’ resplendent in her headscarf and carrying her shopping.

As the wages and lifestyles of these players took them away from the worlds inhabited by the supporters the Lisbon Lions began to fill the gap. No event, it seemed, was too remote or occurring at too short notice for at least one of them to attend.

The significance of this can never really be overstated. As the working man and woman’s game became a multi-billion-pound global and capitalistic enterprise the Lisbon Lions helped maintain the spiritual bond between Celtic and the supporters. They kept this club grounded.

My friend Alex Gordon, former sports editor of the Sunday Mail, became the unofficial chronicler of the life and times of the Lisbon Lions. In their later years he helped them to set down their memories in books and articles so that their feats could be reached by the newest generations of Celtic supporters.

Alex told me once about an occasion when Bertie Auld arrived at Parkhead to conduct a book signing event. This was at the height of the Martin O’Neill era when, perhaps for the first time, Celtic had assembled a squad full of millionaire superstars.

“As the fans began to notice that Bertie was in the vicinity they turned their attentions away from those players and flocked towards him,” Alex recalled. “Of course they adored Henrik and his team-mates but I think they all just wanted to show Bertie that he and the Lions would always be loved by them.”

When I watched Jim Craig take his seat on Saturday it also struck me that I’d never seen a Lisbon Lion without a smile on his face. None of them were ever reluctant to tell us about their Lisbon memories and their stories about playing for Celtic. They’ve always been available and never seem to tire of the company.

Several years ago, I heard a senior Celtic marketing executive express disdain for all the Lisbon anniversaries and how it was a tiresome circus about the past and that it was time to move on. They simply failed to understand the spiritual bond that these men kept strong between Celtic and their supporters.

There will never be a time to “move on” from the Lisbon Lions. They represent the best of Celtic and have given more to this club and generations of its supporters than anyone else. And none of them ever became rich for it. No amount of fetes, galas or gilded commemorations can ever truly salute what those men did for this club and for the rest of us.

There should be an official Lisbon Day on May 25 each year. It would be Celtic's own Robert Burns Day and be celebrated by supporters around the world. It would also ensure that these men and what they represented will remain immortal.