Fallacious yet widespread and documented beliefs courtesy of Wikipedia.
Humans have more than five senses. Although definitions vary, the actual number ranges from 9 to more than 20. In addition to sight, smell, taste, touch, and hearing, which were the senses identified by Aristotle, humans can sense balance and acceleration (equilibrioception), pain (nociception), body and limb position (proprioception or kinesthetic sense), and relative temperature (thermoception). Other senses sometimes identified are the sense of time, itching, pressure, hunger, thirst, fullness of the stomach, need to urinate, need to defecate, and blood carbon dioxide levels.

Fallacious yet widespread and documented beliefs courtesy of Wikipedia.
Shaving does not cause terminal hair to grow back thicker or coarser or darker. This belief is because hair that has never been cut has a tapered end, whereas, after cutting, there is no taper. Thus, it appears thicker, and feels coarser due to the sharper, unworn edges. The fact that shorter hairs are "harder" (less flexible) than longer hairs also contributes to this effect. Hair can also appear darker after it grows back because hair that has never been cut is often lighter due to sun exposure.

Fallacious yet widespread and documented beliefs courtesy of Wikipedia.
Hair and fingernails do not continue to grow after a person dies. Rather, the skin dries and shrinks away from the bases of hairs and nails, giving the appearance of growth.

Fallacious yet widespread and documented beliefs courtesy of Wikipedia.
Hair care products cannot as such "repair" split ends and damaged hair. They can, however, prevent damage from occurring in the first place, smooth down the cuticle in a glue-like fashion so that it appears repaired and generally make hair appear in better condition.

Fallacious yet widespread and documented beliefs courtesy of Wikipedia.
Eight glasses of water a day are not necessary to maintain health. Consuming things that contain water such as juice, tea, milk, fruits and vegetables also keeps a person hydrated.

Fallacious yet widespread and documented beliefs courtesy of Wikipedia.
Sugar does not cause hyperactivity in children. Double-blind trials have shown no difference in behavior between children given sugar-full or sugar-free diets, even in studies specifically looking at children with attention-deficit/hyperactivity disorder or those considered sensitive to sugar. The difference in behaviour proved to be psychological.

Fallacious yet widespread and documented beliefs courtesy of Wikipedia.
Alcohol does not in fact make one warmer. The reason that alcoholic drinks create the sensation of warmth is that they cause blood vessels to dilate and stimulate nerve endings near the surface of the skin with an influx of warm blood. This can actually result in making the core body temperature lower, as it allows for easier heat exchange with a cold external environment.

Fallacious yet widespread and documented beliefs courtesy of Wikipedia.
Alcohol does not kill brain cells. Early temperance writers promoted the idea that drinking causes brain cells to die (as well as the assertion that the alcohol in the blood stream could cause people to catch fire and burn alive). According to Queensland Brain Institute director Professor Perry Bartlett, there is no evidence that drinking alcohol leads directly to the death of brain cells. In fact, alcohol has positive health benefits when used moderately and new brain cells are generated on a daily basis. Alcohol can lead indirectly to the death of brain cells in chronic, heavy alcohol users whose brains have adapted to the effects of alcohol, where abrupt cessation following heavy use can cause excitotoxicity leading to cellular death in multiple areas of the brain.

Fallacious yet widespread and documented beliefs courtesy of Wikipedia.
A vegetarian or vegan diet can provide enough protein. In fact, typical protein intakes of ovo-lacto vegetarians and of vegans meet and exceed requirements. While lower in protein than non-vegetarian diets, adequate but low protein diets have been shown to be beneficial against cancer. A non-vegetarian diet high in protein such as a typical diet in the United States in fact has been shown to be linked to several diseases including osteoporosis, cancer, impaired kidney function, and heart disease.