If I hadn't realised that before, it was certainly brought home to me while curating the collection of images submitted by more than 50 contributors to our newest book, Newcastle, by Itself: 2000-2020.

So many of the images depict scenes that can no longer be found, while just as many show the new views that have taken their place, making this volume a handy permanent record of a remarkably eventful period.

The book came about when, as the year began with a storm of anxiety about fires, drought and the global pandemic, we found ourselves locked down and wondering what sort of project we should tackle this year. We've produced a book a year since Newcastle, The Missing Years in 2010, and we aren't ready to stop yet.

My wife Sylvia had been talking for some time about putting together a book of contributed digital images - ever since a discussion about the potentially transient nature of digital data compared with the relative durability of old-school photographic negatives. While it's never been easier to share images, it's also shockingly easy to lose them.

Digital data might seem more durable, but hard-drive failures, flash memory corruption and technological change means the opposite may often be the case.

We put the word out that if people wanted to send us some favourite images we would try to make a book of them, with a format similar to our previous volumes. We had about 50 contributors, and with a backbone of material from some big contributors - including Ron Morrison, Phil Voysey, Pete Smith, Art Ryan and Matthew Ward - the book took shape.

Curating the collection, it became clearer than ever what a period of change the first 20 years of the 21st century has been in Newcastle and the Hunter Region.

Taking Newcastle itself, consider the closure of the railway station, the removal of such well-known structures as Surf House, the Queens Wharf tower, the Palais Royale and the introduction of dramatic new elements such as the tram, the law courts and university building and the massive city precinct redevelopment now under way.

The contributed material covered a broad spectrum. From the beautiful aerial images submitted by Mark Goolmeer, the evocative light-paintings of Pete Smith, the quirky spur-of-the-moment observations captured by Phil Voysey, Art Ryan and Matthew Ward to the more documentary recordings of Suzanne Martin - overlaid by a scattering of personal moments from other contributors - the ingredients were ample for the recipe.

I've got my favourites. Sharon Smith's cracking image of the Palais during the Pasha Bulker storm - shot from a car window with raindrops on the glass. Pete Smith's Pasha shot, with the ship looming huge between the surf club buildings at Nobbys. Nic Brady's shot of his daughter catching raindrops in her mouth on King Street. Matthew Ward's pictures of girls in the rain at Newcastle Show. Mark Goolmeer's epic shot of the rescue helicopter in the grounds of Singleton Hospital. Jodie Patmore's haunting image of the dry bed of the Barrington River during the drought. But actually so many more ...

Our dear friends Ron and Liz Morrison provided a hard-drive packed with digital images from around the time they were working on their own book, Newcastle, Heart of the Hunter and collaborating with John Armstrong on a book about Port Stephens. This tremendous collection of material was extremely helpful.

Halfway through the project I was ready to swear I'd never tackle anything like it again. Now, seeing the finished product and liking what I see, I'm almost wondering if I could possibly change my mind.