As most Londoners will agree, the sense of euphoria during last summer's Olympics disappeared more quickly than Lance Armstrong after a call from the doping inspectors. No sooner had the athletes flown home than the festival sites packed up, and commuter life was duller without a tracksuited Games Maker in every rail carriage.
But the factor most to blame for London going cold turkey was, perhaps, that the Olympic Park — the focal point of the event — was off limits to the public within hours of the end of the Paralympic closing ceremony.
Many felt that Boris Johnson, by allowing the gates to be padlocked, surrendered to the demands of engineers and project managers to have the whole site back for conversion work. The feel-good factor had been unnecessarily snuffed out, it was claimed.
This week, I took a tour to check on progress of the £6bn makeover of the Lower Lea Valley, and learn of the Mayor's plans to connect the Games site to the residents who have been promised so much.
Media trips past the security fence have been strictly limited in the six months since the Olympics — and first impressions confirm why. Much of the park has the feel of a building-site-cum-ghost-town.
Nature plays its part in this bleak picture, as our Land Rover is buffeted by Siberian winds and snow flurries. The park had sported gardens, blooming meadows and lawns, but now the only dash of colour is a few primroses on the riverbank by the media centre.
Some of the venues where dreams were made or broken, and spectators thronged, now have a haunted feel. The basketball arena and water polo complex are being dismantled, the hockey arena has long since disappeared. But undoubtedly the biggest hole left behind is the absence of spectators. At peak times during the Games it felt like Oxford Circus at rush hour as up to a quarter of a million ticketholders criss-crossed the park. Where there was once a sea of flag-waving humanity, the packed thoroughfare that had been overlooked by the BBC studio is now being turfed over.
Mr Johnson, a Games evangelist, has insisted the Olympo-sceptics who had been confounded by the success of London 2012 will be proved just as wrong about the legacy of the park.
The Mayor made himself head of the London Legacy Development Corporation weeks after the Games — ruthlessly sidelining the incumbent — in a considerable boost for the prospects of the project. The corporation has hired much of the expertise from the London 2012 construction agency, the Olympic Delivery Authority, and has a £292m budget for converting sports venues, removing temporary arenas, building a new road network, and landscaping (the amount of parkland will double).
On our tour, we enter at the southern gate of the site, where construction of a new Docklands Light Railway station at Pudding Mill Lane is in full swing. It is being rebuilt as the current one is located at the site where Crossrail — which will serve Stratford — comes to the surface.
Ahead is the most difficult piece of the legacy jigsaw, the Olympic Stadium. The absence of building work is a reminder that its fate is still unconfirmed, although West Ham expect to be granted long-term tenancy this month for the 2015/16 season. Work to build a corporate tier and add seats over the running track can then begin, although it probably will not be finished in time to host the 2015 Rugby World Cup, as organisers have hoped.
Next to the stadium, the tarmac is slowly receding and will be replaced by a "South Plaza", with tree-lined boulevards leading to outdoor "rooms" for theatre and play spaces. It has been designed by James Corner, creator of New York's acclaimed High Line, a park created out of an old elevated railway. The eastern fringe of the Olympic Park is separated from Hackney Wick by a canal, and a new bridge will provide an entrance from the east.
It will halve east-to-west walking and cycling times from Hackney to Leyton, and is an example of how the ultra-secure island site is being connected to the boroughs surrounding it. Just further north, the copper-clad handball arena requires only minimal alterations — a new gym and a café — before it is ready to host a variety of events, from basketball matches to large Asian weddings.
Nicknamed the Copper Box during the Games, it and the Aquatics Centre will be run by venues operator GLL. GLL hopes to turn the Copper Box into a "mini O2 arena" to subsidise the cost of the aquatics centre, set to open next spring. Its neighbour is the Olympic broadcast centre, into which BT Vision moved recently in order to build studios for their Premier League football coverage, starting next season. The future of the vast Olympic media centre remains uncertain until the iCITY consortium, proposing a "digital cluster", can convince the Mayor it has enough tenants to create the 4,500 skilled jobs pledged to the taxpayer in return for meeting the £330m cost of building the facility. In the far north of the park, across the A12, Eton Manor — host of Paralympic tennis — is being converted into a tennis and hockey centre. The corner of Hackney Marshes, lost to an Olympic coach park, is being reclaimed for footballers in time for the new season.
The basketball arena will soon vanish — its fabric skin is being peeled back by abseilers — to clear the site for Chobham Manor, the first of five new neighbourhoods, with 850 homes.
In contrast to the adjacent high-rise Olympic Village, which will have its first tenants in late summer, Chobham Manor will comprise low-rise terrace homes, one in five of them for families. Children will attend Chobham Academy, and use an adventure playground by the designers of the Diana Memorial Playground in Kensington Gardens.
The park is already well connected by Tube and rail, but the opening of Waterden Road in May will improve links for motorists. This north-south route through the middle of the site will allow traffic to turn off the A12 and drive through to Westfield shopping centre, and beyond to Stratford High Street. The tree-lined road could also be a case study for the Mayor's bike revolution, as there will be segregated lanes for cyclists, pedestrian-friendly low kerbs, and a 20mph speed limit.
The north section of Queen Elizabeth Olympic Park is set to open in July. Londoners will get to judge progress when it hosts a series of anniversary events this summer, with Bruce Springsteen and Jay-Z playing.
Usain Bolt, Jessica Ennis and Mo Farah will be in action in the stadium on 27 July, a year since the Games' Opening Ceremony.
The south section of the park is timetabled to open in spring next year. But experts agree that the true verdict on the Games legacy — as measured in thousands of new skilled jobs and homes — will, depending on the economy, probably not be delivered for another quarter of a century.