Ethics and Moral value judgements

Lots of people I talk to talk in terms of the “good” and “bad” …they talk about ethics and morality.

Where do we get these moral values and value judgements from? Are they just based on conventional values of the society or family unit/workplace/philosophical school we have been raised up in?

Isn’t it a bit dumb to follow the same values everyday and in each instance and not change our values (as per the context and situation). Just curious what ethics I should follow…

“Is it better to do the right thing for the wrong reasons or to do the wrong thing for the right reasons? (ignoring context)”

I have had this discussion many times in my life. I believe the answer lies in the following question I asked myself: what decides whether an action is good or wrong?

i.e. how do we know whether we are indeed doing the right thing? After all, we have all heard the phrase: “The road to hell is paved with good intentions…”