I was the same way...but that was because deep inside every fiber of my being, I knew - without any doubt - that my success or failure in life will have absolutely no connection with my school grades. I knew it as young as 15 or 16...but of course nobody takes you seriously at that age, especially when you start talking about life. At the time, when I tried drilling that concept into my parents' heads, they thought I was insane. But it turned out that I would ultimately be vindicated, as my grades and education as a whole had absolutely ZERO impact on my life.
If you really feel that going back to school will help you out in the long term with your career and overall quality of life, then it's definitely something you should consider. But make sure you weigh the pros and cons properly, because many people have gone back to school in their late 20s and 30s, only to regret it later because it had little or no impact on their salaries and career in general. Certain occupations will definitely reward you for having more diplomas/certificates/degrees, while others won't even give you a second blink.
The problem I'm facing right now is all of the career areas I've been interested in since I was younger require more education, so I feel as though I've closed a number of doors because of my youthful pettiness. I completely avoided mathematics and science in school because my mother kept pressuring me to become a doctor, so my logic was "HAH, I did the bare minimum. Now I CAN'T be a doctor! BEGONE EVIL WOMAN!" It was the small rebellions that kept me sane then. Because I was so determined to not make my mother proud (hah), I stopped caring in general, as I said, and my GPA ended up being a disaster. GRUMBLE GRUMBLE GRUMBLE
