Who you are v.s. What you do

How many times do you have to do something before it becomes who you are? I always try to live by the saying "you are what you most often do". That's pretty powerful when you think about it, your actions become you, your choices become you. 

This thought spawned from a conversation a coworker had with a resident at my job. My coworker called the resident dumb and the resident got offended. The resident made the point that he wasn't dumb because he got good grades but he had been locked up several times for dumb mistakes. My coworker said exactly, you continue to do dumb things with full knowledge of the consequences, Dummy. 

Now his statement might have been harsh but I can't necessarily say it isn't true. How many people do you have to kill to be a murderer? How many tickets do you have to receive before you're labeled as a bad driver? If you consistently do something haven't you earned the right to be called that thing? Think of it on the positive side, if I continuously do well in school and achieve high levels of education haven't I earned the right to be called a scholar? If I'm on time for everything I do aren't I punctual? We are what we most often do and if you don't like it, DO something about it.