Growing up in the 80s and 90s, retard, fag, gay, etc, were all words that were thrown around without any thought whatsoever to their impact on people. To me, none should be acceptable to throw around in public anymore. I'm not perfect, however. I've been able to eliminate 'fag' from my vocabulary, and severely limit 'gay', but I occasionally use 'retarded'. It's something that I consciously try to not use, but old habits die hard. It's not a word I would choose to use, but sometimes reactions happen faster than thought.
I was essentially about to make the exact same comment, thanks for saving me the time. Growing up in the same era (relatively speaking) as you, I struggled with these three words as well. Like you, fag is gone, gay kind of stuck around a bit (but when I say it it never has anything to do with homosexuality and I literally don't mean it as a slur) and retard is the hardest to get rid of completely. -I wonder why? It's definitely the most socially acceptable still.
Same boat here, a few years in Boston has made "wicked retarded" the one that slips out the most. I used "Indian Giver" one time and I jumped on by the language police. I always thought it referred to how the White Devil would "give" the Indians stuff like the land they already owned and take it back but evidently it's about Indians acting just like White Devils and is offensive. I don't think I ever used it again. I still use queer in the traditional sense of the word and am not giving it up. In an example "I had a queer feeling of deja vu when the bloody clown emerged from closet holding the ferret." I don't accept that the word can not be used in the sense that it was used for a few hundred years because it's become a substitute for homosexuals in both a laudatory and derogatory sense. It's easier to get rid of gay, retarded and fag when they were always derogatory but a good honest word like queer is one that I have trouble censoring because it's connotations in my use are completely harmless, there is no negative energy bundled up in it's use to red flag it for me. I think if I naturally used the word gay to mean happy I'd feel much the same way.
This is about what I was going to say to a tee. I used to say gay/retarded. I had a teacher who broke the habit of saying retarded for everyone I know. I rarely say it, it is an extremely offensive word. I never got into the habit of saying fag, but gay was thrown around constantly when I was a kid. I stopped using that one when I found out one of my close friends was gay, as well as my brother. I felt really guilty every time I slipped up, so the habit was pretty easy to break.
I never use the words "retarded" or "gay," but my friends and I throw around the word "fag" a lot. I suppose I think of it as harmless, seeing that I've been in a homosexual relationship and honestly don't give a flying fuck. I don't care if my friend calls me a faggot. I don't care if a stranger calls me a faggot. If I'm acting faggoty, then call me a faggot. This of course transcends the main definition of the word in our culture. It has been redefined (at least around where I live) to mean something along the lines of "douchebag." Using the word as such is mostly non-offensive. If you're using the word "fag" to negatively compare someone to a homosexual, that's not okay.