Human behavior and why it baffles the clueless

So yesterday, someone told me I shouldn't have been offended by their offensive behavior.

So after I had to "get over it", I also had to get beyond the idea that someone who knows nothing of me outside of my professional environment honestly believes they can tell me what I am allowed and not allowed to take offense at. Whenever someone tells me that I should or shouldn't feel a certain way, they get filed in the people I really don't want playing an important part in my life. But why is this anyone's response? I mean, I don't respond this way. If I offend someone, inadvertently or not, and I am made aware of it by them, I will apologize, correct my behavior, and move on. I will not tell them that they shouldn't be offended by my behavior. I especially will NOT continue in the behavior that caused offense and think all is well because I instructed the person NOT to be offended.

I mean, THAT sort of behavior would finger me as a clueless fucking idiot.

This exact scenario happened to me by a person I will loosely call a colleague. If she brings it up AGAIN, I'll explain to her exactly why her behavior is offensive. For the second time. Maybe she needs repetition for it to sink in.