how is having thick skin a bad thing? I wish my skin were thicker, I'd like to not crack under pressure so easily, then I could speak my mind. The only thing I have a thick skin for is my art, because I understand that in order to get better, I have to take criticism and critiques, and not take them as shot to who I am personally.
You have a balance of being emotional and rational, and have a good sense to know when you should be sensitive or a thick skin, and that comes with experience.