To tell you the truth I learned very little in school when contrasted with the 12-years I spent there. Many guys I know can hardly even read or do basic math like division and fractions after all those years.

What the hay were they doing all that time and why did they get diplomas with those poor skills?

Formal education is highly overrated. What really counts is what YOU put into it. Don't just aim for a rag of a diploma. Reach for REAL knowledge and understanding of the world. When you study reach for deeper meaning and not just to pass a test. In the long run you will grow into a full human being and not an expert test taker.