As I understand Carnival, darkly, leg-pulls are an essential part of the fun. For centuries servants have been cocking snooks at their masters, demure young ladies have been planting kisses on the lips of strangers, and broom-waving ski pests have been overtaking on the inside and whacking us on the backside as they speed by.  It’s Carnival, so we smile bravely and say “Jawohl! Sehr komisch! It’s been far too long since I fell over anyway.”

So the thought does occur to me, as I wrestle with my William Tell costume after an alarm call at 0415 hours, that Lucerne’s advertised carnival timetable might be an elaborate hoax. Why on earth would it start at five in the morning?

I pucker my ruff, fluff up my doublet and make my way down the sweeping grand staircase of the Hotel Schweizerhof, half expecting to find a group of night porters waiting for a good laugh at my expense.   Instead, the pillared hall is filled with harlequins, dandyish beaux and crinolined ladies with powdered wigs, sipping coffee and preparing to step out in to the freezing February darkness.  There are Barbies and Miss Piggys in the mix too. Carnival is not high culture.

Ten minutes later we are all part of the crush on a cobbled square at the heart of the old town: thousands of stupidly clothed people jumping up and down in excitement, or just trying to keep to warm.  It is minus ten and William Tell’s outfitter did not have these conditions in mind.

“The Fritschi Father will come from over there, he always arrives by boat,” yells a man whose halberd is poking in my ribs.  The Fritschi Father is the leader of the carnival, named after …. someone, a long time ago. His arrival will signal the onset of Lucerne’s annual 5 day pre-lent party.   Why the boat?  Don’t ask: maybe the original Fritschi lived on the other side of the lake.

Surely it must be five o’clock by now. I am beginning to lose sensation in my hands. “There’s the Fritschi Father, look, over there!”  Where?  Boom! A cannon report sets off a blizzard of confetti, followed by a bombardment of oranges.   What is this – a joke re-enactment of a nautical engagement, or is there some special significance to the dispensing of fruit?  Are we in a Robin Hood situation here?

“Look, why don’t you stop asking all these questions and just enjoy it,” says the man with the halberd.  “Carnival has its traditions and we act them out every year. Who cares what it means?  It’s fun, that’s all!”

And with that I gratefully give up trying to understand the Swiss carnival, and let Schmutzige Donnerstag – Dirty Thursday – run its messy course.

Once the confetti and oranges have subsided, the bands start marching past, thirty of them including one from Lucerne’s twin city of Bournemouth. There are skeletons, babies with dummies and, striking a rare note of social comment, one miserable black sheep in a smiling white flock.  There will be prizes at the end of the day and my vote goes to a band of Asterix characters and grumpy Roman soldiers.  Through the long winter months the carnival groups, which have their origins in medieval guilds, have been practising their music and working on their costumes in conditions of strictest secrecy.

Musically speaking, the Carnival parade does not aim for or reach great heights of sophistication.  When you’re a baby with a dummy, you’re hardly going to play Mozart’s horn concerto.  Lucerne’s style of drum banging and horn blowing is known as Guggen Musik. Carnival cognoscenti will tell you that the other big Swiss carnivals – Zurich and Basel – specialise in different styles of music. Even so, I doubt they are much more than a cheerful racket.  Zurich follows close on the heels of Lucerne and Basel comes straight after that, so the seriously festive insomniac could plan a two week carnival trip combining all three cities.

I know what you’re thinking: if Carnival is a last blast before Lent, should it not be happening all over the country, simultaneously?  Don’t ask so many questions.  It’s Carnival, and this is how the Swiss do it.  Tourism considerations are not without weight when drawing up the religious calendar.

At the end of the parade the crowd thins and we can inhale and move around the town.  By seven o’clock we have seen most of the bands several times, and an assortment of floats including the Federer family and a rickety cart full of young men in distressed suits – Swiss bankers – holding out their hats for a loan.  We give them a smile (no commitment fee) and straggle gratefully back to the Schweizerhof, where harlequins and crinolined ladies are enjoying scrambled eggs and coffee in the stuccoed ballroom.

This is when it occurs to me that perhaps Fritschi was a skier. Because if I pass on a coffee refill, execute a nifty change of costume – out of William Tell and into ersatz-Willi Bogner – and leg it to the station, I might just catch the 0811 to Engelberg and reach the old monastery town and new-wave powder skiing pilgrimage destination an hour later: prime time for a ride on the rotating cable car to the glaciated steeps of Mount Titlis. Failing that, I could catch the 0911, and still not be too late for a full day on the slopes.

On Dirty Thursday morning the sight of an old fool sprinting along Lucerne’s lakeside boulevard in ski boots passes unnoticed.  Who knows, I might be an obscure satirical statement in the running, so to speak, for a prize.

I catch the train, rent the skis, ride the rotating cable car and pause to catch my breath at the top. What a day!  Far below, Lucerne and the lakes are shrouded in freezing fog, but a strong February sun is blazing on the mountain tops.  The snow is soft, and there are no broom-waving ski pests about.  For mid-February, the slopes are amazingly empty. On Dirty Thursday every young Switzer is banging a drum in Lucerne.

I catch the five o’clock train back to Lucerne and sleep all the way.  The bands are still marching, the horns still blaring, and local youth is looking a little unsteady on its feet.  William Tell, on the other hand, is refreshed, and ready for another long night of revelry.  Demure young ladies, step this way.