I started out in the automotive field myself, and while I truly love working on cars and any form of tinkering. I did notice that the older guys all had issues with arthritis, bad backs, and any other part of thier body that could wear out. Maybe this has changed, but look at the older guys in your shop to see how well they are holding up. I was 22 when I thought about going back to school and my parents offered to pay for it so I went to college and only play with cars as a hobby now. My opinion is that people who are naturally mechanically minded, like mechanics, tend to do well in math, physics, and engineering courses. Language and the arts come more difficult for me.
When I got my first job I found out years later that my supervisor, who was raised on a farm and was extremely mechanically minded, would only hire engineers who were capable of working on thier own car. The fact that my resume showed that I worked in the automotive field before going to college was a plus in his book.
Chris