It's not easy having an underactive cortex. Now, if you have an overactive cortex, there is so much activity inside your head, you can't stand too many external distractions. You organise your sock drawer according to colour and go into a minor psychosis if that system is upset. Still, it's cheap and easy having to spend all your free time at home. I, on the other hand, have a cortex so underactive it can only be described as supine. Nothing goes on inside my head and I need truckfuls of stimulation to be able to function. Fortunately, I've had the mainland to give me all the stimulation I have needed to keep that turtle-like cortex dragging itself around at 1cm an hour. However, after 26 years, inspiration has been starting to wear thin. Shenzhen is used up; last month, by visiting the aircraft carrier Minsk I had officially been everywhere in that fast-growing city. Anyway, it's just a big city and, with no harbour for neon lights to mirror themselves in, it's even tiles-and-metal uglier than Hong Kong. The towns that are reachable by bus from Shenzhen are old hat, too; it's not enough to just go somewhere, I have to go somewhere new. But the new places are five or six hours' away by bus; too far for a weekend trip. My friend A, he of the GPS and idiosyncratic shopping habits, came to the rescue, again. "Ferry!" he said. "Ninety minutes from Tsim Sha Tsui!" Since then, I've been taking ferries more than any other form of transport. Advice: if travelling on a Saturday, buy your tickets online a few days in advance. Avoid the 11.40am ferry to Zhongshan, as it goes via the airport, adding 25 minutes to your meticulously planned schedule. Don't assume "luxury class" is better than economy. If anything, the cabin is more cramped and the "luxury" comes in the form of a limp cake and a see-through plastic cup of light-brown dishwater masquerading as coffee. In economy, while you must fork out all of 15 yuan (HK$19) for coffee in a styrofoam cup, you get to choose its strength! And the amount of condensed milk! Instead of having to battle the line-cutting hordes at the Lo Wu crossing, which has the added irritant of a 15-minute queue for the unmonitored baggage X-ray machine, by taking the ferry to Zhongshan you enter the mainland through a largely empty visa control area from whence you can reach literally hundreds of towns in a short time. My cortex is leaping with joy. By the time it has used up the Zhongshan area, someone will have invented a faster kind of transport. Right?