How did London become the greatest city in the world? When I lived there in the mid-80s, it had no such claim. Down-at-heel and drab, there was no inkling of the swan it would become in the next century.
When I slumped poverty-stricken into a diseased lung of a flat bordering Clapham Common, a jogger had been murdered in broad daylight the week before.
Clapham itself was supposed to be slightly posh (hence 'Cla'hm', as it was pronounced by the Sloanes), but you could have fooled me.
The pubs were dingy and streets dirty. Restaurants served barely edible food, unless you went backstreet ethnic.
Simmering unrest was everywhere, particularly among the black communities of south and north. The riots were still fresh in the memory and stop-and-search was still the Met's idea of community policing.
Still, London was exciting. It always has been. A ferment of new ideas, culture and experimentation.
It tended to suck you up, exhaust you and spit you out to the suburbs when you could take no more. Travelling on the Tube was like working down a mine. People emerged blinking and sooty-faced after hideously long commutes. I still have friends who have lived there from that time. They have the London smugness, of course, see me as hopelessly provincial (you mean you haven't seen the new David Hare?!), but now have a point. For London has become something to admire. It is a place of fabulous surprises, a city always on the move, of course, but now with purpose.
There is still a huge divide between the offensively rich and the depressingly poor and much of its sheen comes at the price of housing the rapacious City and its largely unpleasant masters of the universe. So hardly solid foundations, but it is the other people of London who have given it renewed vitality.
It has always been the end of the line for 'refugees' seeking a new start, whether that be from provincial England, Ireland, or Nigeria. More than 300 languages are spoken among its eight million people.
Despite what you might read in the Daily Mail, multiculturalism has worked in London. Yes, there is still hideous racism, corruption and occasionally a willingness to exploit London's good nature and openess to preach hate.
But the peoples of the world largely live cheek-by-jowl, scratching and scraping a living, relying on their wits, starting cottage industries, powering the local economies of London every bit as the Square Mile. And that has driven up standards everywhere.
In the shadow of the hideous Shard tower is Borough Market, nestling under the railway lines out of London Bridge station. When I lived there, you'd be lucky to buy a mouldy cabbage from a bloke who looked like Jack 'The Hat' McVitie. Now it is a place of wonder, full of colour and the most fabulous foods, fresh fish, vegetables from around the world and not a Costa in sight.
It's just one of the pockets of London that have been transformed. I was there last weekend and began wondering about our own big city, Belfast.
It will never match the scale of London, obviously, and much of it is still blacked-out and derelict at night. Forgetting what positive contribution multiculturalism might have made back in the dark days, can we learn from the Smoke of today?
Do we have an overarching vision of where our powerhouse city is going? We have citizens desperate to move forward, but do we have the politicians and entrepreneurs to lead us?
Are we proud enough of Belfast to put aside our psychological divisions and work together without worrying who's getting a bigger slice of the pie? Who is bold enough to put their head above the parapet and become the city's champion?
We have the desire, the talent and the young people with a new mindset. And that is more than London appeared to have in the polluted, surly, monochrome mid-80s.