No, and neither did you.
Examples of very bad behaviour devised by a person following his own imperfect conscience: failing to stop at a traffic light and causing a car crash; refusing to help put out somebody else's fire; seducing a colleague's wife.Because for some people, relying on their own moral comapasses would yield some very bad behavior.
(The monsterly behaviour of individuals is not a result of reliance on their sense of right, but of overruling it. Criminals and abusers know they're doing wrong. Demagogues are sometimes unclear on the concept.)
Examples of very bad behaviour resulting from people ignoring their own conscience and blindly following national and religious leaders: Crusade I though XII; WWI & II; 9/11
Why and when did we switch from speaking of good behaviour to speaking of laws?[Those who do - Where did they learn it?
Those who don't - Why not?]
We were speaking there of laws, not behaviors.
I'm aware that the knowledge of law varies widely in the population - and that the law considers ignorance of it no excuse for breaking one.
But that's very different from a personal sense of what's good and fair. Personal conscience often drives the righteous person to oppose an immoral law.