Then the Government chimes in. The country is littered with nagging advertising campaigns. Don't smoke, don't drink, slow down. A lot of time and money is spent on harassing people into doing the right thing.
Adults are mentally strong enough to ignore these messages. Kids aren't. If you're not careful your children will use what they're told against you.
This is exactly what happened to me.
I'd had a massive day at work. So I figured I'd have a cheeky puff in the car on the way home. Just to relax. I don't smoke. Well, just the odd one here and there for old time's sake. I'm not addicted or anything. I just like the feel of delicious nicotine running through my veins.
Obviously I don't want my kids to follow my example. So I carefully covered my tracks. I drove with all the windows down. I hid everything. Chewed a mint.
The perfect crime.
Or so I thought. But my 5-year-old was on to me the second I walked through the door. "Have you been smoking Dad?"
I had no choice but to look him square in the eye and lie "no way, I'm not stupid". "Why do you smell like smoke Dad?" "Um, there must be a fire somewhere, we should probably run out on to the street." He didn't buy it.
So to distract him I told him we could play video games instead of doing his homework. He liked that. I was home free. Phew.
Suddenly it all went horribly wrong. A fag fell out of my jacket on to the floor in front of him.
Busted.
My boy had seen a "smoking kills" advert. Like any good son he doesn't want his dad to die. Which is fair enough. I'm a lot of fun.
So he delivered me a stern telling-off. Humiliating.
I promised I would never smoke again then bought icecream to shut him up.
That night I got revenge by making him eat twice as many vegetables as usual. It felt good to get one back.
Children catching parents being naughty isn't a new thing. The issue was covered brilliantly in Cheap Trick's killer 1978 song Surrender.
"When I woke up, Mom and Dad are rolling on the couch rolling numbers, rock and rollin' Got my Kiss records out." But these days more and more things are being deemed naughty. This makes getting busted increasingly likely.
There are speed display boxes on the side of the road so your kids can hassle you for driving at 52km/h. There are people appearing on television everyday to tell us off for what we eat. Soon you'll get in as much trouble for putting sugar in your coffee as I did for my tasty little puff.
The good news is you don't have to take any of it on board yourself. Good parent aren't saints. They're just good at hiding their many vices from their kids.
While you're telling your kids off just take a little time to get your lies together for when they catch you.
I didn't have my story straight and it cost me dearly. Three hours playing Batman Lego, an icecream and my dignity. I blame the Government.