It is true that some people do know themselves at a very young age, and some do remain similar people throughout their lives so that their initial choice always suits them. However, the vast majority of people make choices in their teens and early twenties that fail to last the distance, and land up bored and disappointed with "life, the universe and everything".
What can you do though when you're stuck with the choice? Or are you? Let's look at some options:
Option 1: Change your career. That's fine if it's something you're able to do either with a side-step or by taking your current training and abilities and applying it to a different field or a different role. Not always possible though. Sometimes it would require a salary sacrifice that you can't afford to make, or you're too bespoke in your abilities and they aren't transportable, or the options just aren't available in the area in which you live.
Option 2: Take up further training. This could be done through work, in your spare time, as a correspondence course, or during the weekends. You could train in something that will enhance your opportunities in your current role, or something completely different that will re-launch your career along more interesting and hopefully lucrative lines.
Option 3: Take up a hobby. Sometimes you can't change your career for good reasons, perhaps because you have your entire future invested in staying right where you are, but you can create a life around that job that is fun and fulfilling thereby diminishing the importance of that job thereby reducing it to the vehicle that creates the fun. Supposing for example you take up art, you discover that you are a brilliant artist, you paint some paintings, have a show, sell your work and so on. One day you could own an art gallery! All arising from a happy hobby intended to take your mind off work.
Option 4: Change your attitude. If you insist on treating work only as a necessity two things will happen. Firstly you'll accept misery at work as part of that necessity. Secondly you won't 'own' your work, accept it as a real part of your life guided by your own choices, and therefore feel able to embrace what you do and change it if you don't like it. Allowing your job to drift and you along with it is refusing to make a choice, which is of course a choice and a bad one. Getting hold of your career and accepting that it's yours, a vital part of your life for many reasons not an optional nuisance, creates great power for change. Sometimes all you need to do is to decide to feel better right where you are, and better options open up almost like magic! After all, your boss will promote a smiling, positive, 'can do', happy to be here employee over a misery any day.
Whatever you do, do something. A job is almost always a life necessity - or most people wouldn't work at all. So accept that you have to work and then go out and seek whatever it is that will ensure that you never work a day in your life. As Confucius said "choose a job you love and you will never work a day in your life".
I do love my work, my work is my life is my passion is me. I'm not lucky, I had a career I hated and I worked and made sacrifices to change it. I'm not a hero either, I'm just someone who doesn't like to be unhappy. Nor should you.