German is my third language, and since 2009 I am learning Austrian German by immersion, so for just some idle Friday fun I will now try to translate that to Viennese:

"Ihr soid olle Depperten zu glauben, aus Eurer Erfohrung wos zu lernen zu gön, i zieh es vu, aus den Fühlern ondrer zu lernen, um oigene Fühler zu vüümoiden."

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.