Light the flame, or should that be touchpaper?

The Olympic opening ceremony will ignite the greatest show on earth but we might all be raging by then. No matter, it will be worth it

When the Olympic flame, now winging its way from its ancient cradle in Greece, lands here on Friday, organisers believe the slow-burning fuse attached to London 2012 will finally ignite a Games fever that envelops the nation.

The symbol of Olympia arrives at RNAS Culdrose, near Helston in, Cornwall, for a round-Britain relay starting at Land's End. Cornish-born triple Olympic sailing gold medallist Ben Ainslie is the first of 8,000 torchbearers carrying it through over 1,000 cities, towns and villages to the lighting of the cauldron at the opening ceremony in the Olympic Stadium in east London 70 days later.

The identity of the person who adds the final flourish to London's seven-year journey approaching midnight on Friday 27 July will remain a closely guarded secret.

Whether it is another old Olympic flame like Sir Steve Redgrave or Daley Thompson, or a complete unknown from 2012's own Olympic heartland in the East End is a decision to be made by an independent panel in collaboration with Lord Coe's organising committee and the British Olympic Association – along with Danny Boyle and his co-producers of the opening ceremony, such is the anticipated showbiz element of the £80m curtain-raiser.

The torch relay is about to propel the 30th Olympiad to the forefront of our consciousness. But are Londoners themselves ready for what will hit them once the five-ringed Olympic circus rolls into town?

As yet London has no idea of the magnitude of the jamboree that will dominate our lives this summer. Even less the inconvenience it will cause along the way. This is a Coronation, a Royal Wedding and a Queen's Jubilee all rolled into one, lasting not just a day but around three weeks. The last time the Games were here, in austerity-gripped 1948, it was by necessity a relatively low-key production. This time it truly will be the greatest sporting show on earth.

A life-changing experience, even? It will be for those living in London who can have little conception of the baggage the Olympic flame is about to bring with it. Welcome to Lockdown London. We can anticipate an unprecedented ring of steel around the capital, not just to protect 17,000 athletes for 17 days and the subsequent Paralympics but for several weeks before and after.

Operation Olympic Guardian will see the biggest mobilisation of militia, police and security forces since World War Two and it is certain to have an impact on all our lives.

More troops – around 13,500 – will be deployed than are serving in Afghanistan. The security force being assembled by G4S, the world's largest security company, is expected to total almost 50,000. Machine guns will be toted by guards on the Tube. Police special forces will wear balaclavas to avoid identification. At times London may seem like a war zone.

During the aircraft carrier HMS Illustrious will dock on the Thames and surface-to-air missile systems will scan the skies. Unmanned drones will loiter over stadia patrolled from above by helicopter gunships and Typhoon fighters. A thousand armed diplomatic and FBI agents will patrol an Olympic zone partitioned off from the wider city by an 11-mile electric fence.

With roadblocks and security check-points across the city, stop and search will be the order of the day. Any demonstrations that might disrupt or disfigure the Games, which are always a magnet for protest groups, are likely to be proscribed by law.

Getting around London will be a nightmare because of congestion and road closures. And not just the East End. In the West End the Mall, Horse Guards Parade and most of St James's Park will be closed from next month onwards. Even Transport for London are advising Tube passengers: "It may be quicker to walk in for part of your journey." It will take 20 minutes to walk to the Olympic Park from the nearest alighting point at Stratford.

Inevitably a "them and us" divide will be created by the Olympic lanes, a city-wide system which will allow 4,000 VIPs from the Olympic family – and the media and sponsors – to be shuttled to and from the Olympic Park. Those at Heathrow Airport who have recently been held up for two to three hours are being warned by immigration staff: "If you think this is bad, wait until the Olympics."

So is it all worth it? Absolutely. Once the Torch is lit and the gold rush starts, all the aggro will be forgiven if not forgotten. Even if there's a bit of an overspend. And when Jacques Rogge, president of the International Olympic Committee, proclaims London as the greatest ever Games, the plaudits will be piled as high as the Shard. Meanwhile let's get ready to grumble.