We’ve all made mistakes.
We still do.
We will continue to.

However, the first mistake rarely brings any harm.
Ignoring the mistake and not learning a lesson from it causes real harm. 

Because we’ve wasted a learning opportunity.
Because we might repeat the same mistake again.
Because we have let a life teacher go by without giving us a lesson.

Committing mistakes is not the mistake.
Not learning from them is.