When I was in school, I wasn't interested in studying. I didn't understand why I would ever need chemistry or physics calculations in my daily life. The truth is that probably you don't. So, I was pretty right in that. I didn't open a book when I was younger. My idea of school was not wrong. A huge majority of the stuff is worthless and has no real value in real daily life.
However, now that I am a bit older, I have started to gain some interest in molecular cell biology or any science. I am glad I had some very basic lessons on the topics, even though I didn't really follow those lessons attentively. But I may find these topics interesting now, the truth is that they won't make me any money. And I am very dependent on that money for my basic needs to survive. Reading books is interesting and important, but you don't get paid for doing so in a direct way. There are a lot of people studying things like philosophy, history, and chemistry at universities but struggle to find decent jobs in their fields afterward.
It is great to start something in science out as a hobby or side hustle and just experiment with it. Only if you're smart, putting in the effort, and if you're passionate, you can very maybe find a job for your highly specific field in some university or some business (where you will need to sign a lot of NDAs). But the change is also very likely that you put in a lot of effort and don't get any money for it in return. The person who learned a field (electrician, plumber, etc.) and started out a small business that generates an income has probably been the smarter one. The chance of you creating the next big business based on the scientific knowledge you gained is very small and probably not worth the risk.
To cover basic expenses, you need to find a way to get an income to cover your basic needs. It is not easy, and often, it takes a long learning curve of many years to do it based on theoretical knowledge (university years, first jobs, etc.). This means it's a huge investment for yourself because you're not earning a lot in the beginning of your career and for the company hiring you because they will need to guide and assist you a lot in your work the upcoming years and you're probably working to slow for them. If you're not a super talent you will find it very hard to find a decent paying job, especially if you're just starting out. The amount of science based jobs are very limited and competitive. They often times won't give you much freedom anyway. I am reading books and study and experiment with scientific topics during my free time but oh darling, I don't want to depend on theoretical knowledge to earn an income for me.
Some people manage to write books or create content around scientific topics, but without proper knowledge it's only given to a minority group of individuals to commercialize that. Scientists are actually very dependent on private money and businesses to survive. It is a separate topic of its own.
I must note that there are exceptions like civil engineers or doctors, for example. They will probably find a good job and will need there theoretical knowledge on a daily basis to do calculations and all that kind of stuff. But unless you're born very smartly, the average person has no change in ever succeeding at getting a civil engineering degree. The same rules still apply do. You will need a long learning curve with a huge investment from starting university toward being 'a profitable civil engineer'.
The rules applied here apply to many modern day professions. Back in the day professions where quite simple. You baked bread, milked cows or made some goods by hand or with the help of some simple materials. Modern day jobs like software engineers or bio-chemistry engineers are often times heavily subsidized by governments in the form of universities or grants to companies hiring inexperienced people. Everybody needs breads, but not everyone needs a biochemist for example to survive. I must speak against myself and noting that even simple professions back in the day have become more complicated in today’s society. Even a baker will need to learn machinery to bake his or her bread. Yet, It shouldn’t be a process that takes years to be able to bake bread.
It can be interesting to read a 500-page study book about for example molecular cell biology. But the effort I put in it, let's say I spend at least a couple of full months on it, that's a couple of thousands of euros it costs me from an economical perspective because I am not working, plus if you want a microscope or some other materials to more fundamentally experiment and try certain things the costs run up quickly and the gains are ...€0.
Aldo it's financially maybe not going to earn me a penny, I will still read and follow theoretical sciences. Maybe I find some practical use cases in writing articles, talking to people or hosting podcasts.