I am right there with you. I hate when I am talking and then just ... completely forget the word I'm looking for. I can see what it is in my mind's eye, but can't spit it out for the life of me and so I just stand there staring blankly at the person like an idiot while they just blink at me while I take up to a full minute to spit out this one word. It would be okay if it only happened once in a conversation - but it can happen for multiple words in a sentence. It's beyond frustrating for me.