Throughout our lives, we have so much information about how to take care of ourselves thrown at us that it can be hard to weed out the truth from the half-truths -- especially when it comes to our skin's health. Hot water vs. cold water? Physical vs. chemical exfoliation? Serum vs. oil? There are some hard and fast "rules," so to speak, that science has proved worthy of following. Answer these questions to see if your skin is the healthiest it can be!