As a teenager you get asked, "What are you going to do when you grow up?" rather frequently.
This question is often overlooked. It seems straight forward at first but there is one problem. When you eventually, "grow up," you are going to spend the rest of your life doing this thing.
Naturally when one is asked the question, you will get an array of answers. But there is one question I would like to ask in response.
"Do you love it?"
This is what it all comes down to. Are you truly passionate about the thing you want to do when you grow up? I wouldn't be surprised if most people said yes, besides you want to look like you're following your dreams. Everyone wants to have their future mapped out for them.
From my rather limited time on this planet, I would argue that people have an alternate driving force behind their decision. It could be family, it could be a friend, it could be a safe bet or it could just be the based off the subjects you are best at. "I'm good at mathematics. I should become an engineer or an actuary."
This should not be the thought process. It is actually very simple.
You should ask yourself, "What do I read in my spare time? What do I think about after I've done my homework? What videos do I mainly watch on YouTube?"
The answer to these questions is your passion. Whatever it is you just have to find a creative way to now make a living out of it. And now you can live your life doing what you love. After all, we only have one life. Why waste a day doing something you don't love.
As a side note, many people will say, "But what if I don't have a thing that I do in my spare time?" It depends on what you consider spare time. Spare time to you, may be the time after your workout. The time after your jam on the guitar. The time after you played with your dogs. If this is the case, then your passion possibly lies in fitness, in music, in animals. Sometimes the things you do during the day outside of your 9 to 5 are your passions.
Listen to them. Do what you love and you will leave a legacy.