Recently, I've been experimenting with a technique, which I learned from the fabulous book "The Einstein Factor" by Dr. Win Wenger and Richard Poe. In "The Einstein Factor", Dr. Wenger states, that you can increase your I.Q. by becoming able to have lucid dreams. A lucid dream is a dream, that you are aware of and that you can manipulate. The way to get there is to tell yourself over the course of the day every now and then, that "This is NOT a dream". You could also ask yourself "Is this a dream?" a couple of times a day. It is a great experience to be able to modify your dreams, especially your nightmares! As a child I used to have a recurring nightmare and by lucid dreaming I was able to stop it by telling myself: "This is just a dream. I can simply open my eyes to stop this B.S.". That way, I got rid of my nightmare for good.
However, Dr. Wenger claims, that it's a great training for your brain, if you put paper and pen next to your bed and write down everything you remember about a dream as soon as you wake up and every time you wake up during the night.
For me, it's a very interesting experience to be able to remember my dreams. In addition to that, it's quite shocking to experience your memory drifting away while you are trying to jot down, what you remember of a dream you just had minutes ago. Try it! You might even try to write down your dreams in German words for some additional German training.