There are times when all you can do is marvel. No words, no jokes, no clever-dick remarks; just the awed acknowledgment that you are watching something amazing. The coming days will be full of moments like that. Of joy, of wonder, of disbelief. When you will ask yourself: how on earth do they do it?
The London Paralympics will be an emotional experience like no other. Unlike the Olympics, the Paralympics have never been solely hosted by Great Britain before. Across the country, the excitement is palpable. More than 2.2 million tickets have already been sold, more than the 1.8 million sold at Beijing in 2008. In fact, there are only 300,000 tickets left, which are fully expected to be snapped up over the coming days, which could make this the first Paralympics to sell out.
Tim Hollingsworth, chief executive of the British Paralympic Association, says: "The British public are more excited than even we thought they would be." They are right to be. If anything, this is the real jaw-slackener, the event that will show what humans are capable of. For behind every Paralympian is not just the determination common to all athletes who reach the top. There's that extra shovel of grit that comes from having to overcome the capriciousness of fate.
Take Martine Wiltshire. On 7 July 2005, she was running late for work. Like many Londoners, she was celebrating the news that her home city had won the bid to host the 2012 Olympics. But she chose to take the Circle Line instead of the overground train during her commute from Stroud Green to St Katharine's Docks, and found herself sitting six feet from Shehzad Tanweer. At 8.50am, he detonated a peroxide-based bomb in his rucksack. It was the first of three explosions to rock the Underground within 30 seconds. Trapped beneath mangled metal, Martine was the last person to be rescued from the trian, and lost three-quarters of her blood volume. It was probably only because Elizabeth Kenworthy, an off-duty police officer, tied a makeshift tourniquet round one of her legs that she didn't die.
So when, on Friday, the world tunes in to watch Martine represent Britain in the preliminary rounds of the women's volleyball they will see how Britain – and one Briton in particular – responds to terrorism. Not with a whimper. Not with vengeance. But with a personal crusade to be harder, better, faster and stronger. Her presence among the 301 athletes who make up ParalympicsGB in this week's Games will be the most potent symbol of the stoicism that has characterised London's adoption of the Olympic mantle since that day in 2005. Martine's determination will be a characteristic of all 4,200 athletes from 166 countries taking part in the 20 sports of these Paralympics, the biggest of its kind ever.
Like Tom Aggar. In 2005, aged 21, the 6ft 3in rugby player fell 12 ft on to concrete in the dark during a party. He awoke paralysed from the waist down, knowing that his life had changed for ever. Three years later, he was rowing in the Beijing Paralympics, and won gold in the single scull event. Stefanie Reid was a rugby-mad 15-year-old when she lost her right foot in a speedboat accident. She nearly died from loss of blood, but has since retrained in athletics, partly because her prosthetic limb was considered a hazard for other rugby players. Now, she has christened it "the cheetah". Heather Frederiksen was told she would never swim again after an accident in 2004. But in 2006, watching a former rival swimming in the Commonwealth Games on TV, she said to herself: "I'm not ready to finish. I'll finish when I want to finish, not when someone else tells me to." She won four golds at Beijing.
Theirs are stories of astonishing resilience. Many are also reminders of the personal cost of world events. Like that of Jon-Allan Butterworth, the cyclist who lost his arm in a rocket attack while serving in Iraq in 2007. Or Private Derek Derenalagi, the discus thrower who lost his legs the same year, when his vehicle was blown up by two Taliban mines. Or Captain Nick Beighton, leader of the rowing squad, who lost his legs in 2009 when he stepped on a mine in Afghanistan.
Their injuries testify to the destruction of war. But in the Rwandan sitting volleyball team, there is also a tale of reconciliation. It was founded by two athletes who lost limbs while fighting against each other on opposite sides during the civil war and genocide of 1994. An estimated 800,000 people were killed in about 100 days during the conflict between the Hutus and Tutsis. One athlete lost a leg when he trod on a mine fighting for the Tutsi rebels; the other lost a leg from a bomb while serving in the mainly Hutu army. This week, they will together try to assert their country's position as a credible force in world sport.
But the country that has most cause for pride this week is Britain. No, really. For it was here that the idea for a Paralympic event was born, though perhaps typically for an island of immigrants, it was conceived by a German émigré. As we have seen in the BBC's show Best of Men, starring Rob Brydon, Sir Ludwig Guttman was a neurosurgeon at Stoke Mandeville hospital in Buckinghamshire who tended to Second World War veterans with spinal cord injuries. He wanted to end the perception of paraplegics as lost causes. His idea was that one should concentrate on what they could do, not what they couldn't. His assistant, the late Joan Scruton, later recalled: "They had to do a sport. It was part of the treatment. It was not a question of 'would you like to do archery?'; no, it was part of the treatment, like taking their medicine or doing physiotherapy. And Sir Ludwig would make sure they did it."
In July 1948, to coincide with the London Olympics, he organised an archery competition between Stoke Mandeville and the Royal Star & Garter Home in Richmond. His team lost, but the Stoke Mandeville Games were born, and took place every year from then on.
In 1952, a Dutch team competed, making it the first international event, and in 1960, the first proper Paralympics took place in Rome, a week after the Olympics. Four hundred athletes from 23 countries competed in eight sports, and their packed lunches included a bottle of wine each. Britain did very well, winning 20 golds and coming second in the medal table behind Italy.
There may not be wine this time, but there will be medals. At the 2008 Paralympics, Britain finished second, with 42 golds, beaten only by China. Well, China is so successful now that it almost doesn't count: as one commentator said, China has made silver the new gold. This time, ParalympicsGB is hoping to win 103 medals across 12 of the 20 sports. That is the target set by UK Sport, Britain's central funding body, which has put £49m into the London Paralympics. Team GB well exceeded their target of 48 in the London Olympics, bagging 65 medals, including 29 golds.
Another major difference between now and 1960 is the range of disabilities allowed. The first events were open only to those with spinal injuries. Now, those born disabled are eligible to compete. George Fletcher is a 17-year-old footballer from Liverpool who was born with cerebral palsy on both sides of his body. Despite that, he plays for Everton Disability and in May scored a hat-trick for ParalympicsGB in their 7-0 defeat of the US. This will be his Paralympic debut. Sarah Storey was born without a functioning left hand, after her arm got tangled up with the umbilical cord in the womb. The 34-year-old swimmer and cyclist already has seven gold medals. The weight-lifter Ali Jawad was born with no legs, and has wanted to win a gold medal since he was six. Fate dealt him a cruel blow when, after qualifying for Beijing, he was diagnosed with Crohn's disease, a debilitating inflammation of the gut. He abandoned his sport for two years, but has now staged a comeback, and is ready for lift-off on Thursday.
Here on the sofa, we can't wait. We may have loved the Olympics, but as Boris Johnson says, that was "just the antipasto". This is the primo, secondo, and dolce all at once, the spectacle to round off a year of great British achievement. Plump up the cushions, pour a drink, and raise a glass to the triumph of mankind over misfortune. The Paralympics are coming home. Now let them begin.
Additional research by Chloe Hamilton and Sam CreightonReuse content