It's not unusual for a young adult not to "know" what their purpose in life is. Keep in mind now, the brain is not fully developed until age 25, the last thing to develop is the decision making part of the brain. I have lost count now how many have recalled their late teens and early twenties and think about some bad decisions they had made and then wonder "why" they made such poor decisons at the time. Often they are looking back with their brain first of all fully developed and second of all more life experiences so ofcourse they will wonder about "why" they made bad choices, or did not choose to do more. I have a cousin and when he was your age he had no idea he would end up being a gifted surgeon and figure out how to actually build an esophogus for child that did not have one, nor did he know he was going to perform plastic surgeries on very important world leaders either, or that he was going to give burn victims and cancer victims their smiles back or damaged faces or other damaged areas back either. I remember when he was so shy and somewhat lost, now he has helped build and organize major hospitals and surgical teams. At 22 he sure did not see all these achievements taking place in his life.

However, that being said, not everyone is going to have that kind of big acomplishments, often many accomplish things many never even hear about, but they do make a difference in "some way". My husband knows a guy that was just a bagger at a supermarket and he ended up designing a better way for bags to be separated and now he is very wealthy because all the stores began using what he invented. He was not even college educated, nor was he what others would consider particularly brilliant either.

The important thing to keep in mind is to expose yourself to different things and allow yourself time to develop because at some point you can come up with an idea or lifestyle change that you really end up enjoying, something that right now is not something you can see "yet".