What causes Alzheimer’s disease? Do we only use 10% of our brain? Why is sleep so essential? Is the brain more or less active during sleep? How heavy was Einstein’s brain? Does the size of your brain say anything about intelligence? Why do some people remember their dreams and others do not? Do colours appear the same to everyone? How does stress affect your brain? Can I learn from a text by listening to it while I sleep?  Why don’t we use stem cell therapy for MS?