Over the span of human history, Man has faced many challenges - protecting himself and his family, creating fire, building shelter, building communities and great civilisations, coping with natural and man-made disasters.
Nowadays we have a pretty comfortable existence and are forced to dream up our own silly challenges. Inspired by being in Athens, home of the 1896 and 2004 Olympics, I resolved to run a lap of every Olympic Stadium in the world.
The 1896 stadium was an impressive piece of architecture - a massive horseshoe set into a hill, still in perfect condition 106 years after the last race had been run there.
I approached a man who had been busy taking photographs of the stadium and asked him if he could time me for a lap. He agreed - on the condition he could take some photos of me running round the track.
Somewhere a photo album will now be graced with a picture of me sprinting away into the distance, then returning absolutely knackered 90 seconds later. It was 11 in the morning and the sun was beating down oppressively, so after thanking my official photographer, I collapsed in the shade to recover.
With a spring in my step and a banana milkshake in my stomach, I set off on a long metro ride to the 2004 stadium. Inevitably, with 2 years still to go, this was still a work in progress. The whole site was deserted and railings stopped you getting too close to the stadium.
A rather frustrating trip, but I would return in two years.
While I certainly am in the category of "mad dogs and Englishmen", I'm not a fan of the midday sun so I cooled off for a while in an Internet cafe, and fiddled about in my favourite real world cafe, Cafe Nero.
Later I climbed the hill of Filopappou for some amazing panoramic views of the city, Acropolis and port of Piraeus.
I finished my 'Olympic day' with a wander round Plaka to buy another Olympic T-shirt (I can't help it!) As dusk fell, I made my way to Lycabetus Hill. A funicular whizzed me to the top, where I could see the lights across the whole city.
It was the end of the line. 1500 miles from Ashford to Athens in 19 days. Time to head home.
It started to pour with rain.