Why the usual advice does not work
"Follow your passion" fails because most fifteen-year-olds do not have one yet, and the ones who say they do are often repeating something they heard. "Choose what pays" fails because pay changes, and because a job you cannot stand will not pay you for long — you will leave it.
What works is narrower and duller: find out what actually exists, understand what each road demands of you, and pick one you have a reason for. That is a week of reading, not a lightning strike.
Step one — notice what you already do
Not what you are good at. What you do when nobody is making you do anything.
If you take things apart, that is information. If you argue with the television news, that is information. If you are the one who explains the homework to everyone else, that is information. If you organise the trip, if you draw in the margins, if you keep the accounts of the cricket team — all information.
None of it names a career. All of it narrows the field. A student who explains things to others and enjoys it should look hard at teaching before dismissing it, whatever their marks are.
Step two — see the whole menu
This is the step almost everyone skips, and it is the one that matters most.
Ask a family to name careers after Class 10 and you will usually hear four or five: doctor, engineer, CA, government job, maybe teacher. There are roughly fifty distinct courses you can enter from Class 10 in Karnataka alone, and they lead to more than nine hundred different jobs.
You cannot choose what you have never heard of. Before you decide anything, read every road once — including the ones you are sure are not for you. It costs an afternoon.
Step three — ask what the day is actually like
Job titles hide enormous differences. "Engineer" covers someone writing code in an air-conditioned office and someone standing on a construction site in June. "Doctor" covers a surgeon who operates and a pathologist who never meets a patient.
For any road you are seriously considering, find out three things: what you would do between nine and six, where you would be while doing it, and who you would be doing it with. If you cannot find out, find someone doing that job and ask them. Most people are glad to be asked.
Step four — check what the road demands, not just where it ends
Every road has a hard stretch. Medicine has an entrance exam that takes a year of preparation and years of study after it. Chartered Accountancy has examinations that most candidates do not clear at the first attempt. A construction site is physically demanding in a way an office is not.
The question is not whether you can survive the hard part — most people can. It is whether you will still want to when you are in the middle of it. That is what a reason you can say aloud is for.
Step five — decide, and keep the door open
Choose the next step, not the whole life. And know that the doors reopen more often than families fear: a diploma holder can become an engineer through lateral entry, an arts graduate can enter the civil services, a trade certificate can lead to a diploma and then a degree.
The costly mistake is not choosing wrongly. It is choosing without looking, and then staying because changing feels like admitting something.