I think I'll win the prize for the most ridiculous answer here.

Barbara Streisand.
Allow me to explain.
Barbara Streisand was in the movie "On A Clear Day You Can See Forever" (1970), it's some sort of romantic comedy, I've never seen it, but knew of it.
One of the trailers that played during Brokeback was "On A Clear Day", (2005) a Focus Features film about Frank Redmond, a man who swims the English Channel.
On DCF as Brokeback was nearing the end of its run, we were discussing what we would miss when the movie is out of the theaters. I was reading the thread at work, and someone posted that one thing they would NOT miss was the trailer for "On A Clear Day". I scrolled down, and found the following reply:
" 'On a Clear Day?'....Is that the film where Barbara Streisand swims the English Channel?"
I laughed so hard that people came over to ask what was so funny, and from that day on, anytime I hear "On A Clear Day", or someone mentions Barbara Streisand, that memory pops in my head.