Tristan und Isolde is the ultimate declaration of love

"That sounds different. A bit sad."

I just played F, B, D♯ and G♯. Better known as the Tristan chord. But on guitar. My audience consists of 15 toddlers. They think I drew a beautiful boat and a little later help me draw stars and flowers while singing "Look out! Look out!". We continue, I draw the sea, boats that are late, a big heart and then divide the sketches - the boats and the heart are most wanted, but the castle does well too. That Tristan and Isolde are dead now, but together forever, that's fine too. Nothing crazy about it.

As I walk down the schoolyard, I hear one of the kindergarteners shouting, "look out! look out!" No idea what is going on. Probably one falls off a scooter or from the climbing frame. But the mode of shouting is different. Or am I imagining it? It just might be. The Tristan chord does crazy things to people.

Is there an opera that has as much impact as Wagner's Tristan und Isolde? Philosophers like Nietzsche and writers like Baudelaire devoted well-nigh drunken reflections to the opera, and the mountain of Tristan literature has since reached gargantuan proportions. "This is not music. This is chaos! This is demagoguery, blasphemy and madness! This is perfumed walm, in which it lightens. This is the end of all morality in art!" exclaims the piano teacher from Thomas Mann's Buddenbrooks indignantly when asked to play something from the opera.

Only Mark Twain remained calm and was mostly amazed by the collective madness of the audience: "I feel strongly out of place here. Sometimes I feel like the one sane person in the community of the mad." But "it's better than sex," wrote Jeanette Winterson a century later, "Take four hours of Wagner twice weekly. It will keep you sane and make you better in bed."

Sometimes I think Winterson is right. And I'm sure Twain is right, too, because I felt quite 'out of place' after I first got Tristan und Isolde had seen.

I remember walking down the stairs of the Utrecht theatre afterwards as if dazed. I was walking there and yet again I was not. Rarely was I so aware that by putting one leg in front of the other I was moving forward, meanwhile avoiding the other theatre visitors. That simple act, that everyday reality, struck me at that moment as utterly surreal, indeed, ridiculous almost. The four hours before, in a dark and magical world full of abstractions and artificiality seemed so much more real. I walked out, got into a car, and only a few hours later the 'real' world became somewhat real again. Somewhat, because being against my better judgment and desperately in love with my travelling companion did not help.

But as tempting as it is to find yourself mainly in great works of art, that is not the power of Tristan und Isolde.

I remember a performance in Amsterdam, with maddening staging, but where the overture was launched by Simon Rattle with such breathtaking intensity that a good friend almost started hyperventilating. And in the second act, I gasped for breath myself, when Brangäne's 'Habet Acht' seemed to literally come down from heaven. Naturally, I went again a week later, purely to experience that effect again - Tristan und Isolde is addictive.

But in vain, because Tristan und Isolde hits you again and again, but each time at a different moment. For instance, I did want to pull my hair out at the beginning the third act in Rotterdam thanks to Bill Viola's phenomenal video projections - despite having heard those bars countless times.

Surprisingly, this is not the case. In Tristan und Isolde Wagner pushes the boundaries of tonality, but what makes the music especially special is that throughout the opera, an unbearable tension is built up by invariably working towards a harmonious chord, only to skim away from it at the last moment. It is, to return briefly to Jeanette Winterson, the reverse of ejaculating too soon. Tristan und Isolde is tantric sex, five hours long - thankfully with two breaks to eat and drink.

But to explain that to toddlers.

And there is no need to, as the opera's plot is easily summed up in a dozen drawings and still exciting. The music is similarly easy to simplify. The danger only arises when you work everything out to perfection.

And Wagner does just that. And he was well aware of that potential impact. "This Tristan will be something terrible," he wrote to his secret lover and inspiration Mathilde Wesendonk. "I fear that this opera will be banned - or it must gain the prestige of a parody through a bad performance - only mediocre performances can save me. A successful performance should drive people crazy!"

At God's ventriloquist warns Martin van Amerongen against those who count this opera among their favourites; they are either connoisseurs or completely insane - what am I doing to toddlers? "If you allow Wagner into your life, that life will never be the same again," says Nicolas Mansfield, artistic and business director of the Nationale Reisopera, who sees a dream come true a year after predecessor Guus Mostart said goodbye with Götterdämmerung.

Sound religious?

Damn right!

My father, a Bach lover and church organist, hated Wagner. Now, the beginning of the Meistersinger, that was still possible, but otherwise: "Unplayable junk that goes nowhere that you drown in."

But not if you learn to swim. And I was learning to swim.

Tragedy of a friendship, the controversial performance Jan Fabre, Stefan Hertmans and composer Moritz Eggert made about the relationship between Nietzsche and Wagner that was shown at this year's Holland Festival, concludes with these words:

... what these days
strongly
and vague at the same time
'infinite melody' becomes
named,
man can imagine so,
as if walking into the sea
slowly the steady pace
on the bottom loses
and eventually settled on good luck
surrenders to the waves:
one has to swim.

I remember, how on holiday in Thailand, but it could have been anywhere, I surrendered perfectly happily to a metre-high wave. I got carried away and had to swim. To the beach. To my beloved.

And she smiled.

Just as she smiled years later when I told her that Tristan und Isolde is for everyone, including toddlers, even ours.

Because apart from the countless discourses on that one chord, the philosophical slant and that ode, hidden or otherwise, to Wagner's 'ferne Geliebte', is Tristan und Isolde above all, the ultimate declaration of love to the genre. And thus to life itself.