Everyone has had a few skin care surprises in their day. You pick out a skin care product that sounds like a game-changer but turns out to be a flop (or actually makes your skin look worse), or vice versa. While you’ll never know for sure how your skin will react to a product until you try it, you can have a much better track record if you get to know some of the most popular skin care ingredients and what they do.With that in mind, let’s chat ab...