It is so much better to listen to what people say and do. It means that the person thinks that it is easy to either predict or see by your facial or body expressions what you are thinking or what you will do next. Think of poker players and how they hide their reactions to their cards.
This doesn't mean you can take vitamins or apply topical vitamin C and then bake safely in the sun, but you can help keep your skin healthy and supple by making sure you get enough of this antioxidant vitamin [source: Bouchez].
When topically applied, vitamin C provides a skin-rejuvenating effect by improving collagen synthesis in the skin that slows down with aging, as well as limiting skin damage from free radicals.