But while that decline in collagen happens to everyone, and wrinkles will form along the lines that are moved in facial expressions, sun exposure breaks down collagen even more, leading to wrinkles that otherwise might never have happened.
Fact or Myth: Squinting or rubbing your eyes and face can cause wrinkles.
Wrinkles occur where they do because of the places where skin cells are squeezed millions of times by facial expressions.
As the skin loses firmness with age, wrinkles form where it has been squeezed.
So, squinting, or any other repeated facial expression, like frowning or smiling, will lead to wrinkles when it is done enough times.
But, while facial expressions may be the cause of wrinkles, there's little that can be realistically done to prevent them from forming.
"You can't walk around stone-faced all day," Brancaccio said.
The appearance of wrinkles can be improved with Botox, which is injected in the forehead, between the eyes, to keep the muscles from moving.
Rubbing your eyes, on the other hand, is highly unlikely to leave marks.
"Rubbing can cause irritation or dryness, [but it] won't cause permanent wrinkles," Brancaccio said.
The reason is that people do not rub their face constantly, and even when they do, the rubbing doesn't occur in the same place and in the same direction, which would be necessary to cause wrinkles.
"If you're rubbing your face to the point of scarring, that can be a problem, but most people don't do that," Draelos said.
Fact or Myth? Apply moisturizer and foundation in upward strokes or you will get wrinkles.
"You can't rub wrinkles into your face," Draelos said. "The skin is elastic, and when you stretch it, it bounces back."
Even daily repetition won't be enough to cause a wrinkle if it isn't done in exactly the same way each time.
The only way to artificially create a wrinkle is stretching the skin for a prolonged period -- like when you sleep.
"Sleeping on one side of your face all the time can cause wrinkles on that side because you are creasing the skin in the same way night after night," Kauvar said.
"To avoid that, the best thing to do is sleep on your back. But that's not something everyone can control."
Fact or Myth? Drink eight glasses of water a day and you will have great skin.
Answer: Sort of
Drinking water may be important for healthy skin, but eight glasses may be going overboard.
"You do need to hydrate your skin. However, if you drink too much water, it will just be flushed out," Draelos said.
But she cautioned that dry skin can have other causes.
"Drinking water doesn't necessarily hydrate your skin," she said. "If you have dry skin, it's not necessarily because you don't drink enough water."
She said that moisturizer and mild soap may be the best way to help.
Still, dehydration can have harmful effects on skin.
Kauvar explained that collagen -- the substance that gives skin its firmness -- floats in a sugar gel that holds onto water in the skin. So, without water, the skin can lose that rigidity.
"The key thing is that you want to remain well-hydrated," Kauvar said. "There's no absolute number, and it obviously depends on your size.
Fact or Myth? Bathing in milk (or drinking it) can help you have great skin.
Answer: Fact, but before you head to the grocery store...