Watching the Olympics, one's mind invariably wanders to hypotheticals.
"I wonder how quickly I could run the 400m?"
"Could I throw the javelin more than 40m?"
"What would my tactics be in the 1,500m?"
Silly questions, really. I remember doing the 1,500m at school. Three-and-a-half laps of the athletics track after lunch. It was horrible - and I was sporty.
The only aim was to finish before the fat lad so you could watch him wheeze up the final straight. The PE teacher, keen to misjudge the mood, would always circle the supine finishers attempting to rouse applause for Big Dean as he tumbled over the line. No one ever clapped. Not even his friends.
Watching live, diving is another event where you think: "Yeah - I'd have a crack at that." Probably not an armstand back triple somersault with pike, but I'd definitely dive in.
Actually, I'd definitely jump in... feet first and with absolutely no recourse to spin.
Yet there is one sport I wouldn't just try, but I'd pay to try. Introduced for the fist time at Beijing 2008, BMX racing was seen by many British ticket-seekers as the short straw.
In the run-up to the Games, most applicants could find at least one redeeming feature for whatever sport the lottery had spewed forth.
"What did you get? Diving? At least you'll see Tom Daley."
"Table Tennis? Awesome. The Chinese guys are sensational."
"Beach volleyball? Great - it's like watching Jodie Marsh roll around in sand."
But BMX racing? Sure - Britain is now a nation of cyclists, our love affair with the pedal ignited by success in Beijing, and fanned by victory in the Tour de France, but BMX? That's just men born in the seventies, falling off kids' bikes from the eighties?
Yet inextricably "BMX" has become the star attraction of the second week, with seats for Friday's final the hottest ticket in town.
Not only were the stands packed with the hoi polloi, but David Cameron and David Beckham put in an appearance, sitting together in the blistering London sun, swapping pleasantries about sport, bunny-hops and the sovereign debt crisis.
Perhaps Becks, who narrowly missed out on playing football for Team GB, talked the PM through the disappointment of being dumped by the nation. Give it two years, Dave...
Whatever their subject, the royal couple were as engrossed in this bizarre sport as the rest of the crowd, falling silent as the riders lined up behind a metal gate, and wincing with delight when six women piled-up on the bend.
And that's why I think the "BMX" has proved so popular. It's the crashes and injuries. The Olympics are, after all, nothing more than civilised warfare. Forget IOC notions of friendship or a "celebrations of humanity". This is nation against nation through sporting ritual.
Orwell called sport an "unfailing cause of ill-will". It might seem strange to attach that pejorative to a Games so clearly enjoyed by so many, but witness the Twitter reaction after the US beat Japan in the basketball, or the innuendo thrown at 16-year-old Chinese swimmer Ye Shiwen.
The truce is on, but it is still country against country, with political differences played out on the sporting field, while the mob bays for blood. And with BMX racing, there is a very high chance they will get it.
Or maybe I'm over-thinking this, and people just like the helmets.
Either way, the Games are nearly over, allowing us all to return to our tired little lives without the daily reminder of what could have been had we set our sights just a little higher than finishing in front of the chubby kid at school.
Hypotheticals are banal, but for most of us they're all we have.
...and I'd definitely attack on the last bend of the 10,000m.