> if you step out of this forum and the culture you are in, you will be offended every day

You're not alone, there's just a weird culture in the West at the moment of signalling empathy without demonstrating it. Calling out the usage of a specific word is just an example of it that you've just experienced - don't put too much stock into these people's opinions, even if you get them to "approve" of you all it will take is a slight change in the direction of the wind and they'll burn you at the stake for something else.

Not to mention over time the meanings of these words shift and change because - and repeat after me - language is just an expression of internal thought processes. Eliminating and banning language does nothing to limit the thought processes: people will still want to express the feeling of something being "retarded" even if they cannot use the word "retarded" - eventually the new word being used will be considered "offensive" and the word will shift again but the meaning will stay the same.

Say what you want and stand behind it. Don't let these cry-bullies police your language.