"Laughing or just ignoring the word takes the power away."

This 👆

Using the word in a frivolous and humorous way *diminishes* its power. Being emotionally attached and having a huge reaction to it is what gives it enormous power for no reason.

And being offended pointlessly does something else -- If you are offended "on behalf of another person" because someone used the word "retarded," you are indicating that you believe this word describes them, even though they aren't even involved.

So, in your mind, stop labeling everyone with a mental disability as retarded... because that's not nice. 😁