For those of you who believe you have, leave now, aviation does not have room for the infallible.
For the rest of you, this is how I try to advise students and test applicants not to dwell on errors. “Its not the mountain you just missed you need to worry about, its the one up ahead.”
I see so many pilots who get bogged down by their mistakes and errors which of course is the second hole in the Swiss cheese, the first being the error itself. A good way to think of it is that it is generally not the mistakes you make that matter, its what you do about them. If what you do is beat yourself up, then you are using valuable brain capacity on a pointless and potentially dangerous exercise, which could lead to another error and the inevitable avalanche that could result in an accident.