Can we judge ourselves for mistakes we have no fault?

People told me that I can't judge myself for any of my mistakes because I have no fault, because I didn't choose making mistakes, the mistakes just happened, like a disease. But if I made bad mistakes, it's because they are part of my personality. So how can I not judge myself?

Consider these two things: a disease, what is obviously not a mistake because it's nobody's fault, and a personality characteristic that is not a disease and is a less intense characteristic of the disease. For example: if the disease is narcissist personality disorder, the characteristic is thinking, not all the times like happens in the disease but sometimes, only in yourself and your wills, and throwing water on a dog on purpose (I don't see how throwing water in a dog can not be done on purpose, do you think there is a way?). The disease and the characteristic have the same reason: an unormal personality formed by whatever it is that influenciates a personality.
If we accept the narcissist personality disorder, we have to accept the characteristic of not thinking about other people's feelings: throwing water in the dog, stealing, being rude to people, lying, etc.
Because the disease is more grave (graver?) than this personality characteristic and more intense, and the disease and the characteristic have the same reason. And, although the mistakes described were done on purpose, a person can not be judged for wanting to do wrong things on purpose, and for wanting to treat people and dogs in a bad way, because these two things were not a choice, because nobody chooses his/her personality and the if the person could choose, she/he would choose acting normally. Right?