Well Myself, Intrepid and Azeral have some VERY interesting stories about what we did at school when we weren't in class....
But I will wait to see if they want to share
As for just me, on multiple occasions me and another friend skipped a few classes that we were bored with (generally maths and RE) and we would often ride home from school, in fact, one day I even put on my rollerblades before everyone had gone back into class and we just left....
We got back to my place and were pretty happy with our accomplishment. So we rang Intrepid and left a message asking him to call us (his phone was busy) about 20 mins later the phone rang, my friend picked it up and said "hello?" I was looking at him and waiting to see what Intrepid had to say, but then his face went white and he quickly said in some dodgy accent "I think you have the wrong number" and hung up...
Turns out it was our year co-ordinator, and she knew that we had left.....
To cut a long story short, we got caught and we ended up walking back to school and still having to go to RE
We also skipped another day of school to play backyard golf too, but on that day we also discovered how to use my dad's chainsaw..... Which also happened to be not too long after I had gotten a digital camera