mean what you say, say what you mean

Practising what one preach is a very essential thing for me. I mean there is no point for you blabbing on the hazardous effect of smoking when your teeth are as yellow as a stained toilet bowl that has never been cleaned. Why even bother telling kids that red light means stop when you keep on driving when the traffic light is red.

No use whatsoever in teaching us to plan lesson meaningfully and consider this and that for the lesson but when it comes to your own, it bores us to death.