If you're going to the bathroom in the middle of the night in a hotel, or other strange sleeping site, please feel free to turn on the lights, even it means waking other people up. Trust me. It's a good idea.
This is a tip for those who might run where giant swarms of gnats sometimes loiter by the side of the road. This tip stems from a run on the Mayan Riviera in Mexico, but I've encountered swarms of gnats in Virginia and Kentucky as well. After your run, always stop and look in a mirror before going into public. Otherwise, you might actually complete a transaction at the resort store and greet five people before realizing you have up to 15 gnats stuck to your face and neck.