At a quick count-up, by the end of term I will have attended at least 15 events at DD's school for ONE child! It is a small village school and the school relies heavily on parental involvement.
Harvest festival, parents BBQ, Christmas play, Christmas carol service, winter fete, Christmas school disco and Santa visit, parents evening x3, Easter service, Fairtrade afternoon, summer picnic, summer fete, sports day, end of term assembly x2, end of year celebration and leavers assembly.
And I'm sure I have forgotten some too 
DH works full-time so has only attended a few events, I am a full-time student so have attended most and my grandparents have attended ones that neither of us can make.
Oh, and parents (DH and I included) have given up the odd weekend day to weed and clear the school pond, weed and tidy the school grounds and dig out the new vegetable garden amongst other things. The school staff also volunteered their time to doing these jobs. The HT and parents are pencilling in a weekend in the autumn term, where parents and teachers will come in and fully decorate the school with a fresh lick of paint. We do this because we want to, though - the parish is a very small and close-knit community and the school is at the heart of that.