Smell is one of our five senses. While we often talk about what we feel, taste, see, or hear, smell is a bit of a neglected child. We often only notice our sense of smell when something smells particularly bad or really good. The smell of everyday life? We often don't think about it until it's gone. As anyone with a bad cold can tell you, losing your sense of smell is no laughing matter. You no longer know if food is spoiled, if there’s a gas leak in your house, if your t-shirt needs a wash, and so on. Without your nose, the world is tasteless and dangerous.