I used to hate it when my mom fussed at me about my grammar but, around 4th or 5th grade, I started doing it to everyone involuntarily.
Now, I don't even bother to catch myself when I'm doing it. Also, my mother is like the epitome of learned helplessness and I learned that from her. It took me a long time to get out of that and now, when I catch her doing it, I tell her to just stand up for herself, it's a lot more effective!