On my first visit, some years ago, I passed the time on the long flight from London reading a history of Australian politics in the twentieth century, wherein I encountered the startling fact that in 1967 the Prime Minister, Harold Holt, was strolling along a beach in Victoria when he plunged into the surf and vanished. No trace of the poor man was ever seen again. This seemed doubly astounding to me - first that Australia could just lose a Prime Minister (I mean, come on) and second that news of this had never reached me.