Same Difference

 You've got to love oxymorons,even when you are saying them they sound wrong but they persist. What I'm getting around to are words we use everyday thinking they are pretty much synonyms but they aren't or words we use to describe something thinking it is the only word for the item then find out that wasn't the original name. Confused yet? I am. Take the words couch and sofa,I always thought they meant the same thing and the only difference was regional but that's not the case. Technically a couch is piece of furniture with no arms for lying down where a sofa is  a wooden bench for sitting,though most people consider a sofa a more formal word for a couch. That brings me to the computer mouse,until today I thought that was the only word for it but the mouse actually started out as the turtle!