We shouldn't. If we remember our mistakes, we can move on from them and learn. If we're smart, that is.
The writer Shane Parish, in his excellent blog Farnam Street, quotes Marcus Aurelius on mistakes: "If anyone can refute me -- show me I'm making a mistake or looking at things from the wrong perspective -- I'll gladly change. It's the truth I'm after and the truth never harmed anyone. What harms us is to persist in self-deceit and ignorance," from his Meditations.
Making mistakes isn't the same thing as being stupid. We have a tendency to blame ourselves, or believe ourselves to be stupid for committing errors. But this simply is wrong. When we recognize our errors, we can course-correct. If we want to continue to grow. Those of us who refuse even to consider our mistakes as learning experiences, or to admit mistakes, are the ones who are stupid.
I make mistakes all the time. It's natural -- I'm building a company, and as we figure out the best processes and procedures for working with clients, we don't get things right all the time. But I make sure to acknowledge a mistake and move on and hope to continue to grow.
It's those who refuse to admit mistakes who are dangerous, as the poet Charles Simic wrote a couple of years ago in a blog post on the New York Review of Books site, saying how frightening it is that we've become a nation that no longer applauds intellect but revels in ignorance. Anyone who considers our current political climate, the savagery that masquerades as comments on the Internet and the lowest-common-denominator cable-news universe knows this already.
I'm ignorant sometimes, too. But I certainly don't revel in it. I want to continue to grown, just as I want to learn from mistakes. One important thing I've learned from my mistakes is that by acknowledging them I'm already accepting that I need to look beyond what I did wrong and look to how to do right.