Keep your hands free and your plans open.
Wear it across your body, settle it where it feels comfortable, and get on with whatever you came to do. It stays close without needing much attention, which is exactly what you want when the day is happening around you.
Good for wandering, traveling, running around town, or anywhere you’d rather not spend the day managing your bag. The point is to carry what you need and have your hands available for everything else.