If you think that:

• 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.

Then may be you need to question what you know. Read this quick review of those myths by the BMJ.