- Unnoticed and uncorrected mistakes: Good in the sense that the embarrassment is lessened but dangerous because if you don't make of note of how to do better next time you'll forget.
- Noticed but uncorrected mistakes: These I think are the toughest, with all the problems and none of the benefits of the one's on either side.
- Noticed and corrected mistakes: If corrected well and you take action to change they can actually become good memories with the passage of time and you're able to do better next time.
The difference between negative feedback and correction is important: Negative feedback may or may not be right, it's what you do with it that counts. Correction comes from an ally interested in your well being and who provides it in a safe context. Generally if your open to correction from a certain person then you'll probably on the same page and the correction is something in other circumstances you'd agree with anyway.