Prove them wrong.

When someone tells you your faults, there are several things that you can do.

1.) Accept it as criticism, and learn from it.
2.) Ignore it.
3.) Accept it as criticism, and prove the person wrong.
4.) Simply, prove the person wrong.

Take things in stride. If a particular bit of information hurts, you may want to develop thicker skin. I do recognize that some things cut too deep. I have experienced those things myself; still, there are words that hurt that you can use to build you up. At the same time, there are words that are said in anger that are only used to tear you down. An important piece of advice is to learn to distinguish between the two.

.... but it is always fun to prove someone wrong!