A really weird condition?

i sometime have this little problem but it gets on my nerves so much. i might be talkign with someone and then suddenly forget a word (and only remmeber it in another language, or have it on the 'tip of my tongue') or what i was going to say. and while i am trying to remember it, it drives me crazy and in the case that i dont remember it, it will bug for a very long time as i will still be trying to remember it. Also, last night, i was really tires and almost asleep in bed, when i forgot this prefix in this german verb. I badly wanted to go and find it in my german book, so that i could fal asleep in peace. And yet, until i looked in the book, i could not fall asleep. o.O weird, huh? soo....what is wrong with me?