Once when my English was terrible, my friend told me that a girl he liked had rejected him. For some reason my brain thought that "rejected" meant exactly the opposite of what it actually means, so I got very happy and started congratulating him, telling him how great it was, and how happy I was for him. It happened more than two years ago, but I still feel so terrible about it. It was probably one of the most embarrassing moments in my life lol.