Tuesday's presidential debate was a triumph for nerds around the world.
Hillary Clinton embraced her role as the biggest know-it-all in American politics. She was lame and boring, sure, but she had studied meticulously, and it showed.
Meanwhile, Donald Trump filled the role of loudmouth class clown and decided to wing it.
The result was an incoherent mess, and we should have seen it coming.
"One (candidate) looks to be hunkering down with homework, research and rehearsals, while the other seems to be taking an on-the-fly casual approach to what could be the most important 90 minutes of the presidential election," NBC reported last week.
Other stories backed that up. Clinton stopped campaigning for four whole days before the debate to prepare. She memorised a file of Trump's various scandals and weaknesses, and staged mock debates to hone her answers.
"Clinton has a thick dossier on Trump after months of research and meetings with her debate team, including analysis and assumptions about his psychological makeup that Clinton advisers described as critical to understanding how to knock Trump off balance," the New York Times reported.
While his opponent was busy strategising and building sophisticated psychological profiles, Trump "paid only cursory attention to briefing materials", and couldn't even be bothered to stand at a lectern and sharpen his responses. He also kept campaigning until the eve of the debate, robbing himself of time to cram.
So, to extend the tortured school metaphor we used earlier: Clinton was the student who takes copious amounts of notes and studies for tests weeks in advance, and Trump was the boy lazily scanning his textbook for the first time on the morning of his final exam.
That lack of preparation became more and more obvious with every passing minute of the debate. From about the half-hour mark, Trump's answers deteriorated into rambling streams of consciousness.
Here, for example, is Trump's response to a question about his proposal to cut America's company tax rate.
"They are going to expand their companies and do a tremendous job. I'm getting rid of the great thing for the wealthy, it's a great thing for the middle class and for companies to expand and when these people are going to put billions and billions of dollars into companies and when they are going to bring $2.5 trillion back from overseas where they can't bring the money back because politicians like Secretary Clinton won't allow them to bring the money back because the taxes are so onerous and the bureaucratic red tape, it's so bad.
"So what they are doing is leaving our country and, believe it or not, they are leaving because taxes are too high and because some of them have lots of money outside of our country and instead of bringing it back and putting the money to work because they can't work out a deal and everybody agrees it should be brought back, instead of that, they are leaving our country to get their money because they can't bring their money back into our country because of bureaucratic red tape, because they can't get together. Because we have a president that can't sit them around a table and get them to approve something, and here's the thing, Republicans and Democrats agree that this should be done. $2.5 trillion.
"I happen to think it's double that. It's probably $5 trillion that we can't bring into our country, Lester, and with a little leadership, you'd get it in here very quickly and it could be put to use on the inner cities and lots of other things, and it would be beautiful. But we have no leadership. And honestly, that starts with Secretary Clinton."
The ideal debate answer is clear, coherent and at least somewhat concise. Instead of offering one of those answers, Trump gave us a bunch of scatterbrained, barely relevant run-on sentences with half their grammar missing. That is what happens when you don't practise.
It wasn't an isolated case either. Most of Trump's answers in the final hour followed the same pattern, as he appeared to run out of steam. A full-length mock debate in the lead-up probably would have helped with that.
But mere minutes after walking off stage, Trump was blaming his performance on everything but himself.
"They gave me a defective mic, did you notice that? My mic was defective in the room. I wonder, was that on purpose?" he told journalists.
"I don't want to believe in conspiracy theories, but it was much lower than hers and it was crackling and she didn't have that problem," he added in an interview with Fox News.
Trump claimed he had actually won the debate, citing non-existent polls.
For the record, CNN's official post-debate poll declared Clinton the victor by a margin of 62 per cent to 27. Several online polls gave it to Trump.
Trump's failure to prepare - or even to take responsibility for his failure to prepare - matters a lot, as it exposes him to a potentially lethal line of criticism. You can't be an effective president of the United States if you're lazy.
Clinton started to prosecute that argument during the debate, and it led to her best one-liner: "I think Donald just criticised me for preparing for this debate. And yes, I did. And you know what else I prepared for? I prepared to be president."
It was a brutally effective moment, because while Clinton may be wooden, unrelatable, secretive and dishonest, no one can argue she is unprepared. Thorough preparation is her core strength, and the key feature she's trying to sell to sceptical voters.
Trump could have negated that strength yesterday. He just had to knuckle down, do his homework and give the 80 million Americans watching some reason to believe he was on top of the issues. Instead, he figured he could wing it.
If that ends up costing Trump on election day, it will be his own fault.