I did four years of French in high school. I haven't spoken a word of it since.
The funny thing is, I can remember random phrases, without having much of a clue what they mean anymore. I thought it was supposed to be the other way round - that you forget the words to express what you want to say, not that you remember the words and forget the meaning.
A few days ago, I woke up with je ne sais quoi in my head. I spent the rest of the day murmuring it to myself in quiet moments at work.
KWUH KWUH KWUH!
I remembered enough to vaguely figure it out before resorting to Babel Fish.
Another time, the words je suis en enfant du monde got stuck in my head, in a rather hysterical female voice similar to Lisa Simpson exhorting "I AM THE LIZARD QUEEN!"
Did they even teach us that at school?
"I AM A CHILD OF THE WORLD! (MWUH HUH HUH!)"
I wonder what English phrases ESL people get stuck in their heads.