When I was young, knowing what you wanted to do or be when you grew up seemed easy, a fireman, a policeman, a nurse, a teacher, a shop assistant, a secretary.
These days, people take courses and go to university without having a clear goal of what they want to do when they have finished. With that in mind it seems that it would be difficult to find out what really excites you.
I often use Future Life Progression (FLP) to help people to find what they want, and I have worked with many young people who can let their imaginations run wild once they get into it and therefore experience what makes them feel good.
It is about relaxing the mind, going forward five years and getting a sense of what you may be doing then, but its more about how it makes you feel. The good thing is, because it hasn’t happened yet then you can change course if you don’t like it and bring it too you even quicker if you do.