I skipped a lot in my last two years; luckily my teacher for those periods didn't believe in keeping a register.
It was quite funny actually, because he didn't keep a register, at the end of each term when filling in the report cards he would ask all of us how many days off we had had. I said 'Oh, I think it was just the once' and he said 'Come on, it was more like 47...I'll put 3'