Where Art Thou Words?

Why is that when you are having an intense, important conversation with someone the words you'd like to use go on vacation? I had a talk this afternoon which was about as much fun as a trip to the gyno. I'd prepared a killer speech, but as soon as I saw him the words that I could find were shaky & unsure. Of course as soon as I left I had my Celine Dion moment and it all came back to me. FML.