Some may say medicine. I do not think so. It is expensive to become a doctor and you might just end up paying your debts a few years after you graduated.
Medicine is not as expensive as you painted it, my friend, a little money added to an average program will hand you that certificate in most countries. Besides, have you thought of a scholarship? If you are brilliant and seek for scholarship to study medicine, the chance of you being sponsored is high.
I say information technology or Computer Science.
I knew this was what you would choose, well, it's good if you are good at it. The truth is that not everybody has that coding brain, so what should become of them?
a person needs to study for 15-20 years as minimum.
20 years to study medicine? Which country is that? 6-7 years is enough to study medicine, others will be paid-practical training, so you have nothing to lose as you are already earning. So long as it's what you want with your life, why not? This wasn't even aligned with my former response, which focused on the fact that money shouldn't be a barrier to studying medicine if the person could afford to pay for other causes.
Lets start with which area of medicine you are talking about? Within 6-7 years who you will be? In our European country its a nurse (study + practice for which you will earn minimum wage). There are not scholarship or there is something like 2-5 places among 150 students. Can someone become rich by working as a nurse?
You are making me laugh here, bro, as if we do not have medical friends in Europe or have access to information online, and again, you don't use Europe to judge for all countries. For starters, if you hear Medicine as a course, it is what produces medical doctors in different sectors, and not nurses. Nurses study nursing, and their roles are clearly different.
In that understanding, I am referring to medical doctors, their study won't take more than the average of 6-7 years in all countries, including Europe (in a university as an undergraduate). Perhaps you included the time they will become a certified doctor, if you do, then you are mistaken about the context from the beginning, as it's limited to when they graduate from the university until they start earning, even if it is 1 cent. Their pay may not be as huge as that of a certified doctor for a while, but earning is earning, and this pay increases as the training and experience increase.
As for the scholarship, it was never a basis here, it's just a suggestion for those who are less privileged financially.