I wish chewing gum hadn't been invented. It's filthy bloody stuff, and gets everywhere. Walk on any pavement in central London after a rain shower and look down - there's millions of little white blobs, all of them reminders of someone's gormless mastication and thoughtless gobbing. Ugh!
I did try chewing chicle sap once in Central American, and that was quite good at staving off thirst - but why in the name of anything anyone needs to chew all the time in a city I don't know.
Ah, the joys of the Mudcat - a chance to rant! Gawd bless Tim Berners-Lee and those awfully nice chaps at CERN.
(Talking of which, his original server on which the first web-page ever was hosted just ten years ago is now in the Science Museum in London. And, like every other server in the world since, it has a scruffy sticky label on it with "Do NOT switch off!" in red felt-tip!)