There are certain mysteries in life that scientists will never understand and be able to explain to us in their weird ineffable language. Missing socks in the laundry, for one. Women's moods, for another. The strange bond between men and dogs. And how about the expanding universe and what it is shifting into? Or the way my nephew charges around making strange noises in his own little world. All are completely unfathomable and inexplicable. Another, I have discovered, is buses. The old adage--in England, at least--is that you wait ages for one, and then three come along at once. In Beijing this isn't quite the case. The transport system here is quite impressive. I only ever seem to wait for a few minutes before a bus arrives. Nice. If Britain could run transport so punctually, more people might give up their cars. It is also cheap here. Again, in London a single ride on the "Tube" costs nearly $10. Better start saving for the 2012 Olympics now, the site is miles from the capital.

The bus mystery I wish to expound upon is why my route seems less served than others.

The 104 travels regularly, with half empty buses, coming in packs of two or three with punctual efficiency, always with a smiling driver and charming conductor, pulling in to stop gracefully. "After you madam," "No, kind sir, I insist you go first." Often they are the concertina double-carriage bus with serenely sleeping passengers and, I'm sure, soft lulling music playing. Great. I look upon them with yearning. After perhaps the third 104 pulls away, the 103 arrives. My heart skips a beat and my blood starts to boil. It's packed tight, the driver sneers to the kerb with impatient disdain, usually smashing over a few plant pots and crushing a few feet. The queue transforms into a shark-feeding frenzy: Passengers with bulging sacks of merchandise elbow their way past invalids; little old ladies snarl at little old men; sweet young Chinese girls out muscle their way past me. Initially, I would yield politely; allowing others to go first, before thinking the bus was too full and waiting for the next. After all, buses here are as regular as Chinese dietary habits. Within a minute or two (after several more celestial 104 carriages glide by), the next 103 appears, and suddenly behind me a queue has come out of nowhere, and more suddenly the queue has become a maelstrom, and I am in its midst, swarmed into the bus wondering if my limbs are on board as my neck grazes against another's scalp and my nose explores an armpit.