Mandai, 39 km. My tyre is flat. How does a tyre go flat after I park my bicycle? I expect grit has cut through the tyre into the inner tube. I'm wrong. There is a big hole at the base of the Presta valve. And that's the end of the inner tube; not only is it beyond economic repair, how can such a hole be repaired in the first place?
I change the tube and do interval training for a charity ride next month. Training is boring. As I cycle, I ruminate.
Life has been likened to a roller coaster, with ups and downs. Life has also been likened to a railway track. While one part of life may be up, parallel to it is another rail that may go down. With respect, the second metaphor reflects life better than the first, but is more metaphysical than physical. One rail that goes up while the other goes down spells "train wreck".
For me, life is like an inner tube. No pressure and life is flat. Too little pressure, roll along fine, even comfy, until there's a pinch flat. Too much pressure, explode. If punctured, get to the destination if there's a slow leak. Or not, if it's a blowout and there's no spare tube