Bill Bryson's A Short History of Nearly Everything has sold millions of copies since its initial publication in 2003, but a lot has changed since then.

Bryson had initially retired, but he's since revised his best known work with updated information - and he's set to do a speaking tour, with Auckland and Wellington events to take place in February.

He says a massive amount has changed in the 22 years since writing the book and updating it was a bigger project than expected.

"It was fun, I enjoyed it a lot - I've been kind of retired for a few years and this is why I came out of retirement, to do this. And I really had a good time doing it, it made me remember the joys of actually working."

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