I prefer the English translation, it's more direct, though it does lack the bit about avoiding your own mistakes.

A more literal translation for those that don't speak German:

Those that attempt to learn from their mistakes are idiots. I always try to learn from the mistakes of others and avoid making any myself.

Note: I'm not a German speaker, what I know of the language is from three years of high school classes taken over a decade ago, but I think this translation is more or less correct.