It seems to me there are three elements to a good education:
1. A stimulating environment. In such an environment, everyone will learn furiously.
2. Selection. That is to say, the ratio of useful/constructive things learned, vs useless/wrong/just plain destructive things we learn in the abovementioned stimulating environment.
3. No sugar coating. Nobody who learns only wholesome, proven, positive things will be well educated. An essential aspect of a good education is learning by error and embarrassment, loss, sorrow, breakage, cheating, lying and heartbreak.
So because an education requires fault and deception, there cannot be a perfect education, only a more or less effective one for one’s environment…