Have you ever succeeded in changing a core personality trait?

Disclaimer: This applies to traits that are of importance from a subjective level only.

I swear. A lot. I can put any sailor, teenager, and even Dick Cheney to shame with my expletive skills. I am quite comfortable dropping F-bombs dozens of times each day, every day, no matter where I am or what the situation is (well, not in front of granny, but you get the idea). The thing is, I greatly admire people that don’t use profanity. I aspire to be like them. If I step outside myself I recognize it to be a distasteful and offensive habit that needs rectifying. I think.
At what point (if any) do you stop ‘trying’ to be something that you’re not, and just say to yourself “fuck it, this is who I am”?