Not sure is some missed it, but the comments about "retarted": are because the correct spelling is "retarded". It's like the difference between a moron and a moran.... If you are afflicted with the condition, you likely can't spell the affliction you have.
Also, handicapped is out too....proper etiquette is usually "mentally challenged", or "differently abled". Maybe I am old school, but to me, retarded, mentally challenged, etc, are all the same thing. I would say it is rude to call someone out with those terms, regardless of the term. We all the right to be rude, and also have the right to be thoughtless. At any rate, everyone have a nice day
(more cliches)