Today I drove to work over the Harbour Bridge while everyone else was out celebrating the birth of our nation. For those who don't know, Australia was a penal colony - and January 26 is celebrated as Australia Day, to mark the day in 1788 when a fleet of convict transports from England dropped anchor in Port Jackson, now Sydney Harbour.

It's come a long way in those 200-odd years, and it'd be a revelation to see what the marines, the Royal Navy crews, those first settlers in chains and the bemused local aboriginal people who greeted them as they planted the flag would think if they could see it now: freeways and double-decker trains heading onto the Harbour Bridge, the skyline broken by skyscrapers north and south and miles and miles of harbourside real estate or residential high-rise climbing towards a bright sun in every direction you look.

Helicopters buzzed overhead, and crowds lined the bridge walkway, hundreds of metres above the water, to look back up the blue expanse of the main harbour dotted with boats big and small and past the Opera House waiting for the start of one of the annual Australia Day attractions: the ferry boat race, which begins at Fort Denison, an old island garrison fort sitting in the middle of the harbour, and finishes under the bridge.

Everywhere you looked, someone was flying the southern cross, our blue national flag, with its big white stars and the Union Jack in the corner, symbol of our past and a genuine part of our heritage. Others carried boxing kangaroo flags in the national sporting colours of green and gold. I saw half a dozen red, black and gold Aboriginal flags in amongst the crowds as well, and this morning's activities on the harbour were kicked off by the annual woggan ma-gule spirit cleansing ceremony at Farm Cove in the Royal Botanic Gardens, sacred land of the Gadigal people, which honours our collective past here - whether it reaches back just a few years, a few hundred years or many thousands - and celebrates the hope of the future.

My contribution to the day was to wear a pair of patriotic boardshorts to work, tastefully accessorised with a red, white and blue T-shirt and pair of Brazilian Haviaianas thongs (flip-flops, to those outside Australia) in Aussie green and gold with little Australian flags stuck on them. When you take them off and put them together, the writing on the inner sole spells "Aust-ralia". Beauty. So tacky, I love 'em - even though they're not made here (like most things in Australia today).

And yesterday, despite fears that the flying of the flag would promote racial tensions, worried organisers of the Big Day Out rock concert, which had already been moved back a day from its traditional Australia Day date, backed down and allowed it inside the grounds of Sydney Showground. Co-promoter Vivian Lees, who had at one stage helped organise a rendition of I Still Call Australia Home, admitted that earlier calls not to fly the flag might have been a bit misguided.