It's a pretty rare event when an £800m railway station opens - and an even rarer one in the UK - so it was an invitation readily accepted to be on the first revenue service out of the new St Pancras to Brussels last week.
The previous evening had seen the rather remarkable feat of all Eurostar services transferring lock, stock and barrel from Waterloo International - whose five platforms now stand unbelievably empty - to the sparkling new terminus in north London.
I”m no expert, but I defy anybody, absolutely anybody, not to be completely blown away by what has been achieved at St Pancras and in particular in the fairly timidly-named ”Barlow Shed.”
Some shed. This is a truly colossal space - restored from virtual dereliction not so long ago thanks in no small part to the poet, Sir John Betjeman, whose statue gazing roofwards, graces the concourse.
As I arrived, the Royal Philharmonic Orchestra resplendent in white tux, was playing - a fairly low-key set it has to be said - while hundreds of the world's press replete with squadrons of camera-toting crews - vied for the best vantage point.
My train wasn't due out until 11:04 but at around 10:15, I became aware that the huge station was suddenly filling with hundreds, thousands of people. Most of whom weren't going anywhere.
They had come simply to gawp. To gawp at what has been a staggering achievement and which has the potential to regenerate what is frankly, a fairly run-down area, in the same way that the South Bank now is one of London”s most thriving cultural areas, in no small part due to Eurostar at Waterloo.
Standing head on looking at the six platforms each capable of taking an 18-carriage long Eurostar train, the effect is one of perfect symmetry. That, allied to the sheer power of the skyblue buttresses fitted with tens of thousands of rivets also lends the structure a massive sense of solidity, of power.
It helped that it was a perfectly clear day, but the light pouring through the vast area of glass, was mirrored by the exotic effect achieved in the evening as man-powered illumination lit up the station.
It's not all perfect however. Despite lavishing £800m on it, St Pancras as yet has no business lounge - an extraordinary situation with business premier travellers placated for the time being with some small gifts.
A large swathe of the shopping area near departures is still boarded up, awaiting the final lick of paint and there did not appear to be announcements regarding departures, but maybe this was lost in the hubbub of the first day.
As the 11:04 to Brussels purred past the rather more mundane services to Nottingham and Derby, it almost immediately plunged into the miles of tunnels that set this project apart.
As well as the novelty value of seeing an £800m station, it was also the first time I had used £5.8bn of railway track. Rising and falling through the outskirts of London - and at speed too - it's clear where the money went- this is cutting edge engineering.
Travelling at 186mph is old hat to a Frenchman or Belgian. But to a Brit, hurtling through the Kent countryside at that speed, is nothing short of fantastic. In its literal sense.
There was a small but poignant moment too. Approaching the new station of Ebbsfleet - they of the democratic football team - it'll never work - all the staff lined up in uniform and clapped the Eurostar as it rushed through.
After that it was business as usual through the tunnel, although with the exception that staff were dispensing free Champagne.
Arriving into Brussels we were greeted by one of the strangest bands of all time. Either they were extremely bad and out of tune, or they were being hugely ironic. Either way a bizarre introduction, but they meant well I suppose.
On to lunch at a recommendation courtesy of the Belgian Tourist Board from the day before at World Travel Market - the Museum of Musical Instruments - which is a lot better than it sounds. Set in a classy art deco building near the Royal Quarter, the sixth floor restaurant offers spectacular views over the Belgian capital and the food”s pretty good too.
That left very little time to grab a taxi and head back to Brussels Midi - one of Europe's dingiest stations. Thankfully the business lounge was open - the last time I was in Brussels was on a Sunday and the lounge was resolutely shut.
It's a smaller version of the (former) Waterloo and Paris counterparts, but is kitted out in very much the same way with similar lighting and seats as well as the usual free newspapers/snacks/drinks.
Back into St Pancras and to a halt next to passengers seated at what is claimed to be the world's longest Champagne bar - cheapest glass of sparkling, a wallet-lightening £7.50.
Despite the small niggles - no business lounge yet for example - the overall result of St Pancras is a triumph. And although those living south of the Thames will now have to find their way north, the emergence of St Pancras is hoped to kick-start High Speed II - the development of genuinely quick rail links from the UK midlands and north west to connect to Eurostar and the Continent.
It was also ironic that as Paris was paralysed on the same day by a crippling wave of industrial action, the Brits for once, in the guise of St Pancras could step forward and take a bow. Just for once, we have matched our Gallic cousins - at least for now.