We had one of those discussion at the dinner table the other day. We were talking about school stuff with my daughter and my son was recollecting his school years - he went to the same school as I did. I was explaining something about the uniform at that school to her and my son was backing me up - it was all about how to identify kids who caused trouble between home and school. I then made a joke about when our head of year complained again about members of the public contacting the school about boys smoking outside the school in our year. He then looked at me and my mate and made a very direct comment about it.
I fixed that after then - I lived 300 yrds from the school gates so I would dash home change then go and buy/supply the "fags" to everyone else from the local shop but out of uniform. My daughter said "How old were you then?"... "13" I replied! My wife recounted how she used to watch me leaving school whilst in 6th form for a "fag" and would wave to me from the girls common room. We then talked about uniform infringements. I found there was no clause against waistcoats - so wore an old one of my Dads in grey just to annoy the staff. I was quiet a rebel - I was the only upper 6th former in my year not to be a prefect for example and was always on the school council arguing for better minibuses, uniform relaxations etc. etc.
My daughter however just said "So you were my age and smoking. I'll just go buy a packet then shall I!"
Don't do as I did, do as I tell you to do now... :-)