An unjust criticism is a compliment,
A just criticism needs to be heeded.
How do you know if the criticism is just or not?
Listen, do not react, look deep, meditate, think, ponder, wonder and look at it from the other person's side. If needed talk about it to a trusted friend. If the criticism is right, strive to straighten your ways next time.
If the criticism is truly unjust, let go.
There are no perfect human-beings, not that I am aware of... perfection is the goal while trying to reach which you might run into excellence (Vince Lombardi)! That is good, isn't it?