system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why doesn't water moisturize my skin in the way lotion does? What's the difference?
gpt
Dry skin usually happens not so much because of a lack of water, but a lack of oil, from memory. Without oil, the skin can't create a protective barrier to keep the water in, and it will evaporate. Moisturisers usually include a variety of oils in order to help with this.