Sometimes two hours can pass in a flash, sometimes a whole campaign can be captured in a second and a single, unspoken look.
The most revealing moment last night's leaders' debate was only a few seconds long, but it told the whole story.
There he was, David Cameron at the end of a line-up of seven British politicians, smiling to himself as as Nicola Sturgeon tore into Ed Miliband on spending cuts.
The Tory leader had never wanted to go head to head with Ed Miliband, and when the camera cut away and caught him enjoying the spectacle of the SNP leader going for the Labour leader you felt his strategy was a wise one.
Instead of being held to account, which admittedly he is used to in the Commons, Cameron could lean back for large parts of the debate while six other voices strove to put across their views.
In the opening hour it looked as if things were going to Cameron's plan, which included insisting the Greens be in the room.
From the off it was as if the Coalition had not existed. Nick Clegg, with the biggest yellow Lib Dem tie in Manchester, attacked David Cameron's cuts. But the crossfire from other leaders blunted any direct attack.
There were dividing lines, with the alliance of SNP, Green and Plaid leaders, going against austerity of the three big parties and delivering a vision of the country in accents and words that many other Britons would have found unfamiliar.
All were nervous to begin with. David Cameron's nerves showed through his sweaty, Richard Nixon upper lip.
But the heat was on them all. Three female leaders, the future of politics, four minor parties, five if you count the Lib Dems, had won the golden ticket to a national stage. They all proved themselves accomplished politicians.
But still only one of two men, Cameron or Miliband, can come out as the ultimate winner. It was they who had to escape with no wounds or having inflicted damage on their main rival
Ed Miliband, confident, having taken lessons on his posture, stood firm and said "here's what I believe". He listed what he would do at Prime Minister, hoping people at home could believe he would be Prime Minister.
Farage, with nothing to lose, was the most animated of the line-up. Pinstripe suit and polka-dot tie, he "believed in Britain", and called for control of borders to be taken back from the European Union.
Nicola Sturgeon had the most sophisticated strategy, a message of friendship to the people she wants to make foreigners - the English, Welsh and Northern Irish - while she held out the prospect of "new, progressive politics" at Westminster
She kept pushing and pulling against the Labour leader in equal measure, promising to support him on poverty reduction but not on cutting public services. He couldn't quite attack her, couldn't quite reject her. That could be Miliband's bind after May 7th.
On poverty reduction Nicola said, "I back Ed", and Conservative HQ pumped the line on twitter to feed their narrative of fear about a Labour/SNP alliance.
When the SNP leader turned her fire on Miliband for backing Tory austerity plans her attack was cut short by ITV moderator Julia Etchingham.
But that not before the cameras caught David Cameron smiling to himself. The Tory strategy of setting the SNP against Labour was working fine for him.
Green leader Natalie Bennett tag -teamed with Sturgeon in the progressive alliance against austerity, attacking Miliband, just as Cameron hoped they would.
"Cuts will have to come, "said Miliband. "But we can do it in a balanced way."
It was Nigel Farage threw the first punch, at Scotland. He complained that too much money was "going over Hadrian's Wall".
Sturgeon hit back saying there were no problems that he wouldn't blame on foreigners. Farage shrugged that he wouldn't disagree, and that provided some humorous relief.
But then the UKIP leader engaged in low politics to talk about foreign patients with HIV being treated on the NHS.
Plaid's Leanne Wood, whose warmth won friends, brought him down. "This is dangerous, it stigmatises people and you should be ashamed of yourself," she said to the first outbreak of applause from the oh so quiet audience.
Miliband managed to land one NHS cuts blow on David Cameron. "They believed you were another kind of Conservative," he said, and the sword connected.
He had bought two new pairs of shoes for the encounter, and well he might need them if he fails to come out ahead in the election. We know how time wounds all heels.
So, no clear victor, no gaffes, no losers. But that smile of satisfaction from Cameron, as a left-leaning SNP leader went for the leader of the Labour Party, that was the moment that made Cameron the winner.