Remember the Somme, with 37m poppies, and Kristallnacht. Remember tear gas in Selma, 1965, and tears of joy in Grant Park, 2008. Remember white faces as banks went belly-up. This suddenly seems remembrance year, a year full of "journeys" - and the moment, with the film-maker Terence Davies, to ask what memory means.
The eloquent Davies returns with Of Time and the City - part documentary, part autobiography. The city is Liverpool in the decades after the war. The time is boyhood and adolescence, grappling with homosexuality and a parallel rejection of Catholicism. And now, Davies seems to say, that world is gone. The streets are razed. The kids carouse, fornicate, feel no pain. He is an "alien" in the place where he was born.
It's five-star filming. But, almost accidentally, it touches something deeper: an exploration of how we see our past in compartments, little boxes of memory, through a haze of forgetfulness. For I, too, was in Liverpool for three of Davies' remembered years - and he doesn't quite remember.
Grim-faced lads marching off to fight in Korea? But that war was 1950-53, and Davies (who turns 63 today) was only five at the time. He doesn't really remember. Liverpool's overhead railway? Closed, 1956. The new Metropolitan Cathedral, opened 1967 - seven years after he knew he was gay. A huge BA poster fills the screen, signalling escape? But BA didn't exist until 1974.
Maybe detail, oscillating across a canvas of 20 years, is the enemy of artistic truth. Maybe Liverpool - a seasoned spinner of self-serving legend itself - habitually brushes aside precision. Maybe it was so long ago anyway that dates and scenes are lost without trace in the maw of individual memory. But, sealed, compartmentalised, this ride along the Mersey seems to feed on itself.
But hang on: it wasn't so long ago. It feels distant, because the archive footage used here has a fuzz to it. This past didn't exist of necessity in some cotton-wool country. Its ageing process is more artful than that, designed to let in a certain bleak nostalgia.
Yet the Liverpool of the 1960s was more than the Beatles (who Davies doesn't much like). It was Harold Wilson from Huyton, Shankland's plan for a modern city, Ken Dodd at the Empire, John Pritchard's Philharmonic, Bernard Hepton's Playhouse. The first flat I rented was flattened like the rest of Bedford Street North as the university grew. Goodbye to rats. But hello to something dynamic, hopeful - something absolutely all of a part with Merseyside 2008. And, in the mind's eye, it remains vivid, absolutely without fuzz.
Time isn't buried under tower blocks. It lives on with people, and with the things that bracket their existence: Steven Gerrard, Chinatown, Christianity, a fierce sense of culture. The world of long ago is today and tomorrow's world as well. The biggest drop in house prices since 1992? The lousiest recession since records began? It is often thought we have no grip on memory any longer, as though we don't remember - and cannot learn - so that our lives are trapped in a curious, panicky present.
Rubbish. Memory is a continuum, not a succession of time capsules bolted shut. Today's "journeys" tell a simple truth. 1961: the Beatles first play the Cavern; the 44th president of the United States is born. The futility of the Somme lives and dies again when Saddam's Iraq fights Iran through more bloody years of trench carnage. Compare and contrast Lumumba's Congo of 1960 and today: then weep. And when I walked through Berlin's Holocaust memorial the other day, schoolkids were playing touch round its field of 2,711 concrete slabs. Don't forget to remember, but remember to move on. Memory is a challenge, not a trap: and real journeys never end.
p.preston@theguardian.com
· This article was amended on Wednesday November 12 2008. A reference to Lumumba's Congo of 1965 should have been to 1960. Patrice Lumumba, the first prime minister of the Democratic Republic of the Congo, was killed early in 1961. This has been corrected.
