It comes to me in the middle of the night, that I have been saying "orchestra" when I should have been saying "ensemble." This should have been clear to me long ago, since people often asked, after I incorrectly described our group as an orchestra, if I played strings. This confused me since I had already told them it was a percussion group, but I was patient with them and replied, "Oh, there are no strings."
I was so confident in my mistake (not yet realizing it was a mistake) that they became confused, perhaps some even doubting if they themselves properly understand the word orchestra, maybe being a more general term for a group of musicians, like ensemble? More likely, some of the people I was talking to about the "percussion orchestra" were highly trained musicians, orchestra members themselves, and knew very well that I was mistaken in calling the group an orchestra, but politely let it slide.
There is no good reason why I was misusing the word orchestra being a word I've known all my life, my parents having raised me listening to classical music performed by orchestras.
Once, when I was teaching adult immigrants English, I said that a photo of the Capital in Washington D.C. was the White House. An intelligent Russian man questioned me, but I insisted it was the White House. Everyone was very surprised at how big it was, all for one family! Yes, I agreed, sadly that's how it is here in the United States. Years later, in the middle of the night, I realized my mistake.
There is no good reason why I mistook the Capital for the White House. I had been to Washington. I had seen both buildings with my own eyes. I had been surprised by how small the White House is.