A number of years ago, I was in Lisbon with a friend, when he suggested we buy tickets to watch Sporting play Porto.
I didn't follow football, so I went only with a vague understanding of the rules of the game (get the ball behind the other team's backstop without using your hands), a couple of stock phrases ("well, it's a game of two halves") and a plan to confect some enthusiasm (put money on the game). But in spite of my doubts, I was hooked.
An aspect of football that I hadn't appreciated until then was the camaraderie in following a game with so many fans, particularly in Europe. My friend didn't speak a word of Portuguese, but his arcane knowledge of even minor European football teams gave him immediate non-tourist status and a man-of-the-world ease that I, too, wanted to have.
Through a sort of bizarre - footballing osmosis - he had absorbed geography, history and cultural references from about a dozen different countries. Who would have known that the rivalry between Barcelona and Real Madrid was rooted in the Spanish Civil War? Or that the particularly cooperative style of Dutch politics is also reflected in Dutch football? I'm sure half of what I was told was nonsense - but I lapped it up. And this cultural interest was reciprocal: fans of the other leagues often knew as much about us as we knew about them.
For me, the international flavour of football is part of its magic; for some, like Labour's Andy Burnham, this internationalism is exactly what is rotten about modern football. Following Brexit, he wants a quota on foreign players in the Premier League, who he argues are to blame for the poor state of the English national team. In effect, that:
While there is some truth in those words, what Burnham is describing is also one of the few examples of globalisation working for the underdogs. Luis Suarez once made money sweeping the streets in his hometown of Salto, Uruguay. Now, the force of his talent has propelled him to the top of European football and there are legions of Liverpool and Barcelona fans in Uruguay thanks to him. National clubs without the money to train their own players have also benefited.
Of course, the international character of football has its dark side. Football has always been more tribal than rugby or cricket, where opposing fans mix among each other in the stands. That tribal atmosphere, combined with national rivalries, can sometimes be explosive. Last year, Euro 2016 was darkened by spectacularly brutal fights between fans, in which a small group of highly organised Russian supporters was particularly active. But even here, the story is more complex than simple nationalistic hatred.
In an interview with the British Press, Vadim, one of the leaders of the Moscow Ultras, explained that Russian hooligans grew up modelling themselves on their English hooligan counterparts. Back when English fans were regularly in the press, fighting pitched battles with each other (Millwall even had a 'brick' named after them), the Russian ultras were taking notes.
Over time, most English hooligans have retired - a result of a controversial proliferation in banning orders, travel restrictions, and prosecutions - but the Russian ultras didn't get the memo. Having turned up for a fight with their idols, they found regular football fans instead. At least that's how Vadim explains the video of balaclava clad Russian ultras chasing hundreds of English fans out of a stadium.
I'm not sure whether Vadim's characterisation is accurate, but I like to believe so. Even when football leaves you running for your life, screaming - perhaps a mutual respect between nations lies at its heart.