I went to state school in the late 80s and 90s, I got 10 GCSEs and qualified for 3 A'levels - and I learnt to play an African drum! I now work voluntarily for a charity helping children in Africa, and have been lucky enough to visit myself, as well as working in a full time paid job.
I have always considered that parenal support is just as important in a child's education as teachers are already up against so much. It's great to see how supportive you are being of your son, give yourself a pat on the back, well done.
See, we can all come out with sarcky smart arse remarks when we try :-)