The point is that given it is your child, being near you since day 0, if you give an adequate example of what you consider a good life, they will also be probably inclined to follow your example. Although it isn't a rigorous process.

There is a joke: how do you stop a 30 year old man from beating his wife? You hug him when he is 7. How do you stop a 7 year old from being a brat throwing tantrums for chocolate and YouTube? You control your chocolate/YouTube/etc. intake when they are 1 days old.