So here's what bothers me about using the word "retard" and any of it's variations as insult, adjective or exclamation (please forward to all of your "but I'm an equal opportunity offender!" types):
When you use that word, the people who you are offending the most aren't likely to realize what you're doing and therefore can't defend themselves or respond appropriately to your assholedness. So, if you are a coward, press on! I'll be looking for you. If you'd like to change and grow a bit, find A NEW WORD.