13. Cracking Your Knuckles Will Give You Arthritis
This is still news to most people; cracking knuckles does not actually give you arthritis, but it can leave you in a world of pain. So they were kind of right there, but to go as far as saying arthritis, come on; that is a bit of a stretch. However, be warned that excessive knuckle cracking (which seems to be a bad habit for many people) can irritate your fingers. Apparently this myth was dispelled by a relative of the doctor that initially made this rumor popular (he won a Nobel peace prize for his research). If your own family is throwing you under the bus, you know it has to be a lie.