Good judgment comes from ...

Good judgment comes from experience, and a lot of that comes from bad judgment.
Good judgment comes from experience, and a lot of that comes from bad judgment.

More phrases

If one does not know to which port one is sailing, no wind is favorable.
What a distressing contrast there is between the radiant intelligence of the child and the feeble mentality of the average adult.
We are masters of the unsaid words, but slaves of those we let slip out.
I have always found that mercy bears richer fruits than strict justice.
A lie gets halfway around the world before the truth has a chance to get its pants on.

Quotes from the same author

If you find yourself in a hole, the first thing to do is stop digging.
Even if you're on the right track, you'll get run over if you just sit there.
You've got to go out on a limb sometimes because that's where the fruit is.
A man only learns by two things; one is reading and the other is association with smarter people.
Mothers are the only race of people that speak the same tongue. A mother in Manchuria could converse with a mother in Nebraska and never miss a word.