There's no such thing as an E grade.

... He has a point there o-o

Jonty is clearly not the scholastic type, is he? Then again, I don't think many of us were all that interested in school work during our young teen years. We all were rebellious at one point or another. XD

As for his statement on Geniuses... yes and no. Not gonna go into extensive details, but while some of histories most ingenious thinkers did indeed not have access to formal education (due to the time periods they lived in) most of them were still none the less educated/taught by those before them. Whether it was through being an apprentice or a formal student to said elder(s), they still had proper instruction and guidance in there selected crafts from some form of teacher.