I have made mistakes but not that kind of mistake that I missed any particular contest tag. Because whenever I write an article about contest I remain conscious but it doesn't mean that I didn't do mistakes. Even I did. As I am not trained. I will learn from all the users of this platform.
Secondly, Deleting the post is also bad. At least whatever we do we should take responsibility of it. We should own it. No matter it's bad or good but the point is to learn. If that is bad don't worry it's for learning. We should take lesson and implement on the lesson which we learn.
Learning from our mistakes is what makes the mistakes valuable, if we fail to learn from them it reflects on us poorly.