"All of those cute little plant extracts they throw in, the teeny amounts of apples or chamomile or whatever sexy-sounding herb or plant that grows, that's not what's cleaning your hair," Begoun told "20/20."
"The unsung heroes of the hair care industry are synthetic ingredients," she added. "But it's hard to sell synthetic ingredients as having any sex appeal."
Ingredients like the laureth sulfates are what's actually cleaning your hair, but nobody's touting chemicals on shampoo bottles.
Shaving's been around for thousands of years, and waxing dates back to the ancient Egyptians. Which is the best method for hair removal?
"When you wax the hair, you're pulling it from under the surface of the skin. So it can take several weeks, three to four weeks, before you actually see the hairs resurface," said dermatologist Pat Wexler.
If you shave, Wexler said, you'll see new hair in a couple of days and the hair will grow back coarser. "Because when you shave the hair you're cutting the edge of the hair blunt, so when it grows in you always feel the sharpness," said Wexler.
With waxing, Wexler said the hair will grow back finer. "You create scarring in that hair follicle from the constant pulling," said Wexler. "And the scarring will diminish the number of hairs that grow back."
Skin care fads will come and go, but many of us still hold on to what seems to be the best and most basic way to ward off wrinkles -- moisturizer. Facial creams account for a $250 million a year business, but can moisturizers actually prevent wrinkles?
"They can treat fine lines and wrinkles and improve the appearance of skin, but they are not going to prevent wrinkles," said dermatologist Andrea Cambio. And yet some cosmetics companies promote their products as a method for wrinkle prevention.
"It's very misleading, yes … if there was anything else that could prevent wrinkles that was so easily accessible, we would all look 20," said Cambio. She suggests some things you can do to help. For starters, don't smoke. It's terrible for your skin. And do not leave the house without sunscreen, or a moisturizer with an SPF of at least 15.
Finally don't assume that high price equals high quality. Inexpensive creams are often just as good.
When the lights are out, what if your kids are under the covers reading with a flashlight? Will reading in dim light hurt their eyes?
Dr. Robert Cykiert, associate professor of ophthalmology at New York University, said he's often asked about the myth and it's not true.
"Can it hurt your ears if you listen to a whisper? Of course not," said Cykiert. "And certainly you can't damage your eyes if you read in the dark."
Can staring up close at a television set or computer screen strain the muscles and harm your vision? "Again, totally false," said Cykiert. "You will get some fatigue, you will feel tired … but in fact, that does no damage to your eyes whatsoever."
And if you think eyeglasses or contact lenses create dependency, that's another myth.
"Your eye is either nearsighted or farsighted or has astigmatism because of the anatomical shape of the eye. Then you need glasses or contact lenses or now laser vision corrections to correct that problem," said Cykiert.