Translation - Bulgaars-Engels - Умният човек се учи от грешките си, а мъдрият - от грешките на другите

A smart man learns from his mistakes. A wise man learns from other peoples mistakes.

There is a very good translation available on the internet:
"A clever man learns from his mistakes, but a wise man learns from the mistakes of others."

This one is somewhat clumsy at the end...

Thank you, ViaLuminosa

That's what I thought I wrote there.