I keep seeing people get these expressions wrong. I'm writing them down here so I can link to them later.
- "the elephant in the room" -- The uncomfortable thing that everyone knows but isn't talking about. A drunk father complains "why is everything so messed up?" and nobody talks about the elephant in the room... his alcoholism.
- "white elephant" -- Something you can't get rid of; that costs more to dispose of than to keep. Related: a white elephant sale or auction is a charity event held soon after Christmas where items are sold that have been donated by members. If you received a "white elephant" for Christmas, you bring it to this event and donate it so that the charity can make money and the gift can find a home by someone that would appreciate the item.
- "Seeing pink elephants" -- a euphemism for drunken hallucination. Old cartoons would show a drunk person hallucinating and what they would see is pink elephants.
- "The 800 pound gorilla" -- The big thing that nobody even tries to fight, usually a company; so big they don't have to obey the law or pay attention to competitors. In the 1970s, IBM was the 800 pound gorilla that nobody would even consider fighting. In the 1990s that was Microsoft.
- The 900 pound gorilla. Where did the extra 100 pounds come from?
- "The 800 lb elephant". Mixed metaphor.
- "the white elephant in the room". Mixed metaphor.
- "the 900 pound gorilla in the room". Mixed metaphor; wrong mass.