The Elephant in the Room
The elephant in the room is something that everyone must be able to see yet no one is talking about it. If you went to a party and the host was painted blue but no one seemed to have noticed you would call that the elephant in the room.
"I went to Rogers party and there were lots of people there but the real elephant in the room was that Roger had painted himself blue and everyone just ignored that fact."
The phrase is based on the idea/thought that something as conspicuous as an elephant can appear to be overlooked in codified social interactions, and that the sociology/psychology of repression also operates on the macro scale.
The phrase originates from 1814 when Ivan Andreevich Krylov (1769-1844), poet and fabulist, wrote a fable entitled "The Inquisitive Man" which tells of a man who goes to a museum and notices all sorts of tiny things, but fails to notice an elephant. The phrase became proverbial. Fyodor Dostoevsky in his novel 'Demons' wrote, 'Belinsky was just like Krylov's Inquisitive Man, who didn't notice the elephant in the museum....'