7 medical myths that even doctors believe

According to the New York Times, here they are:

• People should drink at least eight glasses of water a day
  
• We use only 10% of our brains
  
• Hair and fingernails continue to grow after death
  
• Shaving hair causes it to grow back faster, darker, or coarser
  
• Reading in dim light ruins your eyesight
  
• Eating turkey makes people especially drowsy
  
• Mobile phones create considerable electromagnetic interference in hospitals