For me, you know when you've chosen a right career is when you're happy with the job, you're enthusiastic about it and it motivates you to make impacts.
About how to know ahead of time is a good question. I think a good way is to expose yourself to different fields and specific responsibilities of the job. One thing I've learned is that when a degree requires certain subjects/classes, it doesn't mean that those subjects would be applied at work. What you do at work can be very different from what you learn in school. So go online and search for jobs that you're interested in and see what they actually do. For example, if you're interested in Business, search for jobs in Business field, then watch videos or read articles about what those professionals do daily at work. You'll have a good idea of what lines ahead.
Further more, don't be afraid of learning something you're not gonna like. Knowledge is always useful. You might have a degree in something you don't like to work on in the future but it might help you with what you do after that. You can always switch jobs. So just explore around and be open to whatever opportunity that comes to you.
Life is not like a test that has a right answer or wrong answer. When I was a high school student, I don't like biology at all. I like geography, Chinese and chemistry. Somehow, I went to college and got a biology major. I never wanted to be a Ph.D., and now I am a Ph.D. in medical biology. Did I ever give up me Chinese? No, I am also a freelance medical writer. I write the knowledge that I have in a way that everyone can understand. I know some movie stars, singers in the world were once a medical doctor. My professor was a ?singer!
You don't have to set a boundary to limit yourself. Thing and life are changing every day. Something you don't like today, you might like it tomorrow. Something you learned today, might help you ten years later.
Do it, enjoy it and embrace the changes.