Lionel Messi is a player who stirs feelings like no other. He turns sport into art.
Every time I watch him, even on his quiet days, there are moments when you just go 'how does he do that?' He does things three or four times in one game that I probably never managed once in my entire career. He does things no-one else can.
I had exactly the same reaction recently when I watched 'The Last Dance', the documentary about Michael Jordan. I'm not a basketball fan and have never followed it but I loved that series and you could see Jordan's absolute greatness shine through.
Jordan is a very different personality, and much more outgoing, but you could describe Messi in the same way - as an icon whose impact and ability far transcends his own sport. In the same way you don't have to appreciate basketball to appreciate Jordan, you do not have to be a football fan to get pure joy from watching Messi.
Like Jordan, he is simply the greatest to have ever played the game - this is why.
People can make a case for other players being better than Messi in certain areas - for example that Cristiano Ronaldo is a better goalscorer. I would beg to differ, but I can at least understand that argument because there's not much in it in terms of their raw numbers, which are pretty much a goal a game.
But it's not just about Messi's staggering goalscoring statistics. An extraordinary combination of things makes him a complete one-off.
Messi is also right up there with Diego Maradona as the best dribbler there has been, because they both have the ability to ride tackles and get out of unbelievably difficult situations with people all around them.
On top of that, he's also quite possibly the best passer of the ball we have ever seen - he sees things that ordinary mortals don't. It's like he's watching the game from above while playing it at the same time, but even that doesn't do full justice to his genius.
I've watched many games of his at the Nou Camp covering Barcelona in the Champions League and there have been many times when I've seen him hit passes that I and the people around me did not see, and that's when we're overlooking the pitch from high up.
To have that vision and awareness on top of everything else is what makes him incomparable as a player, and such a bewildering talent. Yes, he is a brilliant finisher too, and bends the ball into the top corner of the net regularly himself, but if there's a pass on, he'll play it if that's the right thing to do.
He's not just unselfish, his decision-making ability is exceptional. No-one else does the things he does, the way he does them - and no-one ever has done.
His imagination and skills are unique, but there are other reasons we should cherish Messi while we can, which make him such a great example for everyone to follow.
Messi brings joy to the football pitch - he doesn't play-act or dive and he doesn't remonstrate with referees very often or retaliate to any of the rough treatment he gets.
He benefits, of course, from the law changes that were made some time ago to stop people just hacking the greats down - which is what happened to Maradona, for example.
But the amount of games Messi has played is still amazing, because of the paucity of injuries he has had. He and Cristiano Ronaldo are remarkable creatures in that respect.
That means longevity is another part of the Lionel Messi legend, because he's been doing all this since he was a teenager and he turns 33 in June.
We are spoilt to have had him so good for so long and that is down to his spirit, his character and his drive to stay at the very summit of his sport.
Perhaps Ronaldo's greatness has helped there as well, because they have obviously pushed each other on to even greater heights over the years. But there have never been any off-field issues to distract Messi, unlike the chaos that often surrounded Maradona at his peak, and he belies the myth that geniuses have flaws.
Messi is an interesting personality in a different way, of course, in that he is so introverted. That in itself makes him different from most other superstar footballers we have seen, but it has never stopped him from expressing himself on the pitch.
I have seen Messi play many times but have only met him properly once, through my friend and former Barcelona team-mate Lobo Carrasco, when Barca played Chelsea in London a couple of years ago.
I went to his hotel the night before the game with my boys and he was lovely, posing for pictures and signing their things. He was very amiable and understated and could not have been nicer about everything.
I had actually been in two commercials with him before then, but I didn't meet him for those because he's kind of shy and likes to do those things on his own. It was only the effect of a green screen that brought us together in the same room on film.
So it was great to meet him, even for a fairly short time and, to be honest, I was a bit starstruck. Even footballers can get like that with some other footballers you know - I was similar with Diego.
When I was a player I was in awe of Maradona because of his supreme talent, which just made him seem different to us all. Messi has the same effect of course.
I played at the very top myself, but players like that are at another level still, and you just wonder how that can possibly be.
Before Messi, Maradona was the closest we had seen to the complete package of a player. Pele was more of a goalscorer, and is perhaps more comparable with Ronaldo.
I never thought I would see a better player than Maradona, but when I look at Messi he does everything and more than Diego could do.
The only thing Maradona has got on Messi is a World Cup winners' medal but do you really rank a player's greatness based on that?
If Gonzalo Higuain had taken his chance in the 2014 final, Messi would probably have one of those too, but Higuain missed a sitter and Messi missed out. The difference in the 1986 final was that when Maradona put Jorge Burruchaga through, he scored the winner.
If Argentina had lost that game, would that have meant Maradona wasn't the greatest player the world had seen at that moment in time? Of course not, it's a nonsense. But some will still argue Messi needs to win a World Cup to be considered the greatest, when he has won absolutely everything else.
The World Cup is huge, of course, but it's a knock-out tournament played once every four years with so many other factors at play. In Maradona's time, it was the only time you would see the best players in the world together in the same competition, but things are different now. You have that in the Champions League every season, and Messi has won four of those.
Proving the doubters wrong, time and time again
It's Ronaldo that most people seem to compare Messi to now, not Maradona. People get very tribal in all sorts of ways in life, and Messi versus Ronaldo is one of them.
Often the choice seems to come down to whether you support Barcelona, Real Madrid, Juventus or whoever, which is fine - I understand that.
I am a huge fan of Ronaldo too, but if you're talking about the best player ever, there shouldn't even be a debate that it is Messi. That's just my opinion, but it's not even close for me.
Some people level it against Messi that his achievements have all come with Barca while Ronaldo has won titles in different countries, but I find that suggestion a strange one.
Messi has obviously played in some great teams during his time there but, whoever has been alongside him, his amazing numbers have carried on exactly the same. He has proved the doubters wrong, time and time again.
Even for the past couple of seasons, when the Barca team has not been anything like as strong as it was in the past, his contribution has not dipped. In fact, they have been a real mess without him.
It's rare for any player to stay with one club now, in the way Messi has with Barcelona, let alone someone who moved there from a different country like he did when he left Argentina for Spain, aged 13.
But, if he had left for any reason, Messi would have been accused of being disloyal. He cannot win, basically. And why would he want to move anyway? He started with one of the greatest clubs in world football. Leave Barca and you only move sideways at best. You are never going to move up.
The city clearly suits him as well. Exactly why is not a question I can answer on his behalf, but I know from my own experience that it's a great place to live. There's a massive love for him there, and understandably so.
So it does not look like we will be seeing him in the Premier League any time soon - not that he has anything to prove here anyway. For a long time there was a joke about whether he could 'do it on a cold Tuesday night at Stoke' but absurdly some people have actually questioned for real whether Messi would shine in English football.
I find that totally inexplicable. All you have to do is look at his record against the top English clubs in the Champions League, which is just remarkable.
He's scored 22 goals in 30 games and that's without even considering how he's destroyed teams without getting a goal, which he has done on several occasions. Those are the best Premier League teams, so do people really think he would struggle against lesser sides, from the bottom half of the table? It is a ludicrous argument.
To say that he could not cope physically is a joke. He is unbelievably strong, he is quick and he is powerful. You cannot knock him over, so it's just utter drivel - I only wish he had the chance to show it, too.
It has been an absolute privilege to watch Messi and his last game will be one of the saddest days in football history. No footballer can last forever and you can start to see that his powers are waning a little bit. It doesn't matter how good a player you are - you cannot beat Father Time.
Messi no longer has that explosive turn of pace that he had for years and years - that is what happens as you get older, and it has gradually left him. But even without that turn of speed, he is still the kind of player who can deliver something special.
He can drop a little bit deeper, and he can hit his passes or use his skills to dribble past people. He will still be able to bend free-kicks into the top corner too.
That will all hopefully help him carry on for a few years yet, but reality tells us that we do not have long left of him as a player so we should savour every minute.
We haven't seen him for more than two months now because of the coronavirus pandemic but it looks like La Liga will be resuming behind closed doors very soon in Spain. It won't be the same without a crowd, there's no question of that, but Messi is perhaps the one thing we will be able to enjoy about football without fans.
A bit of Messi, if it is televised, is much needed and will be much appreciated by many - myself included.
Gary Lineker was speaking to BBC Sport's Chris Bevan.