Remember that no one can hurt your feelings without your cooperation and willingness.
Of course, this is completely false.
The truth is that humans are social animals. A significant portion of the human brain is dedicated to decoding and reacting to social signals. If someone deliberately tries to hurt your feelings, you can't help but react to it. It's how you're designed.
"Tetsuya K" seems to be advocating an "independent superman" state. A person in this state would disregard all aspersions cast upon them. It's a seductive idea, because we know that any time we espouse a view or take a stand on something, there are always people willing to argue with us and denigrate us. We all would like the ability to ignore insults. But this goes against our basic nature. Some people might even take Tetsuya's view farther and say that people who allow their feelings to hurt are weak. This is just not true.
Now, I'm not saying we should allow anyone and everyone to influence our actions. I'm saying we should accept hurt feelings as a part of our human existence. We're all created as social beings, and it's pointless to deny that. By accepting that we can feel hurt feelings, that will let us work through them. Having hurt feelings doesn't mean you're weak. Once you accept that, then you can work on moving past those feelings and making sure they don't prevent you from doing what you really need.
Of course, there are people who are able to withstand any sort of guilt or hurt feelings; the common term for such a state is psychopathy.