And I felt the deepest pang of sympathy as I watched the world’s most famous athlete grow old in front of my eyes.
I know Cristiano has been lambasted for storming off in a huff during the Spurs game on Wednesday night.
But you know what, I kind of understood where he was coming from.
I have been in that dark place.
The most terrifying point in the career of any professional footballer is the moment he is confronted by his own athletic mortality, when he can see the finishing line of the only life he has known hurtling toward him like a runaway train.
All sorts of thoughts flood through your mind: Panic, desolation, confusion. You feel terribly alone.
And incredibly vulnerable.
Honestly, it was an earthshattering experience for me – and I had nothing like Ronaldo’s profile.
Now imagine how those sensations must be magnified if you are a global megastar, one of the greatest to have played the game, an individual who has rewritten the record books.
The thought of losing all that, of no longer being able to do the stuff that set you apart from even the best of the rest, can cause you to do the most self-destructive things.
Like refuse to go on to a pitch. Or marching off to the dressing room while your team are still fighting for three points.
It is wrong, but – honestly – I felt Ronaldo’s pain.
Cristiano’s image, his character, his self-esteem all revolves around his capacity to make magic on a football pitch.
He is a ferociously competitive individual, always striving to be the best, certain that he can beat any opponent.
But, though he will rail against the notion, it must be dawning on him that he cannot beat Father Time.
I genuinely believe that is at the core of all that is going on with Ronaldo over recent weeks.
He is enormously frustrated, not so much with Erik ten Hag, but with the ticking clock. He has a big personality and he is evidently struggling to come to terms with the reality that he is no longer The Man.
Cristiano is still in incredible shape for a 37-year-old. I believe he still has plenty to give to football.
But not at Manchester United, not after this last week.
Ten Hag simply had to assert his authority, or he would have been a dead duck leader.
I can’t see how Ronaldo stays at United now. If he is not playing, he is going to be very tough to be around.
A guy at his level of competitive intensity does not have it in his DNA to be bit-part player. I think it is best for everyone – United, Ronaldo, football in general – if he exits.
The issue will be where he might go. Who can afford him? Is anybody going to pay him anything like half a million quid a week? Who will want to take on the baggage of a player who insists on playing every game even as his skills diminish?
I really hope he can come to terms with his new reality.
As he showed against Everton, he can still be a match-winner. I’ve been a huge fan. He has brought so much joy to people.
How many people have made the pilgrimage to Old Trafford over the last 14 months simply so they can say they saw one of the all-time greats in the flesh.
Now it is time for a new chapter.
Ronaldo is not ready to retire, even though he could walk into a role as a FIFA or Portuguese ambassador.
Like so many greats, he is addicted to the incredible adrenalin rush of running out in a packed stadium, with 70,000 pairs of eyes trained on you, watching your every move.
But if he is to remain relevant at the top end of the game – and he is not the kind of guy who you could imagine dropping down a division – he will have to accept a new role.
Maybe as a player who is sprung from the bench to exploit the spaces when a game gets stretched, or perhaps as a player who starts every second or third game.
I hope it works out for him and I would be loath to criticise him for what he did on Wednesday.
As I said, I’ve been there. And it cuts you to the core, gives you a terrible feeling that the walls are closing in.
A brief word about Aston Villa in the wake of Stevie Gerrard’s sacking.
I love the club, I’m on the record as saying I spent the most enjoyable time of my football life there, the way the supporters treated me will live with me for the rest of my days.
But things are not good.
Some of the stories that were being leaked to the press would nearly make a player want to down tools.
A good year for Villa now will be survival. Avoiding relegation must now be the be all and end all.
There is enough talent in the squad.
A new manager who can bring stability and life the mood is vital.