Somebody used to be paid to wake you up
Before alarm clocks were cheap, British mill towns employed a knocker-up: a person who walked the streets before dawn tapping on bedroom windows with a long pole until the occupant appeared. Some used peashooters for the upper floors. They were paid a few pence a week per household, and the job survived into the 1950s.
It is not alone. Lamplighters lit the gas street lamps each evening and put them out at dawn. Cigar factories in Cuba employed a lector to read novels and newspapers aloud to the workers, elected and paid by the rollers themselves. All three jobs were made pointless by a single invention, which is the usual way jobs end.
And nobody had heard of the new ones
The traffic runs the other way too. Somebody's grandparents would have had no idea what a web developer, a social media manager, a drone operator, a data scientist or an app designer was — and most of those jobs pay wages today.
The safest prediction about a child starting school now is that some of them will end up doing something that does not currently exist. Which is an argument for learning how to learn, rather than for picking a job at nine and aiming at it for twenty years.
How many jobs are there?
More than anyone can hold in their head. Official classifications used by governments list several hundred distinct occupational groups, and the American equivalent describes around a thousand separate occupations in detail — each with its own skills, training and daily reality.
Yet most people can name perhaps thirty. That gap matters, because children can only want to be something they have heard of. A CHEF, a PILOT, a SURGEON and a MECHANIC are visible; an acoustics consultant, a hydrologist, a medical illustrator and a patent examiner are not, and all of them are real careers that somebody enjoys.
Old jobs, new tools
Plenty of the work in this grid is ancient. A TAILOR, a BARBER, a MINER, a CHEF and a BANKER would all be recognisable to someone from two thousand years ago, even if the tools have changed beyond recognition.
Others are recent arrivals with old roots: the ENGINEER and the ARCHITECT have been building things forever but now do it with software, and the CHEMIST descends directly from alchemists who were mostly wrong. The sub-topics below break all of it down — hospital teams, emergency crews, trades, farms, shops, kitchens, courts, laboratories and film sets.
What every job has in common
Strip away the uniforms and each one exists because somebody else has a problem. The JUDGE resolves disputes, the WAITER feeds people, the PORTER moves what cannot move itself, the EDITOR makes writing clearer, the SOLDIER is asked to do what a country decides is necessary.
Asking a child which problems they would not mind spending a working life on is a better question than the usual one. That question gets closer to a good answer than the usual one about what they want to be, and it leaves room for jobs nobody has invented yet.