Choosing

I was reading a book on College Majors: How to Choose the Career Path that is Right for you, and I came across a chapter that had me list all of my childhood dreams. It has been proven that at least one childhood dream of everyone has a linkage of some sort to the job(s) that are right for them in the long run.
Here's my list:
1. I'll start with the most outlandish: First Female President of the United States
2. Commercial Airline Pilot
3. Firefighter- only if I got to drive the big red truck :)
4. Musician who plays at Carnegie Hall
5. Brain Surgeon
6. Veternarian- I love dogs and Horses...no Iquanas for me.
7. Professional Ice Skater
8. an Authoress :)
9. A journalist
10. A Research annalyst on a big project like....the cure for cancer, daibetes, arthirtis,etc.
11. Music Teacher
All of these careers I have dreamed about since I was a kid...I used to switch the dream like I switched clothing!
What I want to know is....is it true that we, as children, can dream up a life and career, then live it out? Can we find what we are truly ment to do when we are young?