Mistakes are good¶
A mistake is when you did something wrong. You did or decided or said something, and afterwards you regret it. Or you failed to do or decide or say something that you should have done, decided or said, and now you regret that you haven’t.
A weakness or vice is a variant of mistake that occurs repeatedly as a practice, behaviour, or habit.
A normal and first reaction when you discover that you made (or have) a mistake is to feel ashamed. You try to not tell it to anybody. “I am not going to show others how stupid, weak, unreliable… I am!” You hide your mistake. And if you can’t hide it, you explain to yourself and to others that it actually isn’t a mistake. Such reactions shows that we tend to believe that mistakes are bad.
But there is another possible type of reaction. You can say: “Oh, a mistake! How did that happen? What can I learn from it? How can I avoid it next time?”. You believe that mistakes are good.
Of course I am not saying that mistakes are “pleasant”. Unpleasant things can be good, and pleasant things can be bad.
The problem with considering mistakes as something bad is that it “deactivates” an important aspect of mistakes: They are a fundamental part of our learning process. We need them to grow, to become better.
Nature shows us how important mistakes are. They are the cause of random mutations that arise in the genome of an individual organism, which is a requirement for evolution.
Considering mistakes as something good helps you to be honest with yourself and to grow. It’s easier to say “Indeed, I made a mistake!” when you know that mistakes are not a shame.
Social contacts are easier with people who discovered that mistakes are actually a good thing. If you don’t believe in forgiveness, you develop a tendency to become defensive, combative, to justify your actions, and it can be difficult to converse with you. (compare Nedra Glover Tawwab, via Relationship expert on why it’s hard to talk to some people, Hindustan Times, August 2023.
How other people formulate it:
“Shaming yourself is not constructive. Shame is toxic. It’s not how God thinks of you, and it’s not how God wants you to think of yourself.” says relationship counselor Alison Cook and gives helpful strategies to “fight” your shame. She chose the words “to fight it”, but I guess she actually meant “to welcome and embrace it”.
Considering mistakes as something good is a basic message of the deliberate practice concept, which invites to “a life-long period of deliberate effort to improve performance in a specific domain”.
Every mistake opens a new door. “Fear of making a mistake (…) undoubtedly causes upheaval and stress. But as surely as a door closes, another one opens. The objective is not to stay mired in the loss, but to look for the new door that is opening. They are always there if we learn to look for them.” 
“Die Fehler gehören zum Leben wie der Schatten zum Licht.” – Ernst Jünger
Considering mistakes as something good is a basic element of the Gospel. It is summarized in the creed as “I believe in the forgiveness of sins”. Christians dare to look at their sins because they believe that God forgives them. Yet another example of how human science confirms what Jesus has been telling us for two thousand years (Science confirms the Gospel).