Haha, that kind of thing happens to me all the time. The worst is when the other person doesn't correct you right away - like what happened to you - because then you can't laugh it off.
The other day, a song came on the radio that I thought I recognized, so I said, "Oh, this is such a great song, I love _this band_," to my friend, and everyone around looked at me funny (it was a quiet but populated environment, LOL). Then I realized it was a different song by a different (very famous) band...