I am going to challenge you to try a classic experiment with your sense of smell.
fingers to pinch nose
apple and potato, peeled and cut in to small, bite sized pieces
Put on the blindfold. Pinch your nose. Have someone give you, or you give your child, a piece of apple or potato without telling you which one it is. Chew it up and swallow without un-pinching your nose. What do you think it was? Were you right?
What's happening is that you are using just your sense of taste and not your sense of smell to identify a food. It is much harder for us accurately identify foods without smelling them as we taste them. When we have a cold, food just doesn't taste as good, in part because usually our nose is stuffed up interfering with our sense of smell.
Another fun way to play with smell is to put a few drops of flavoring on a cotton ball, putting that in a bottle or jar, and seeing if you can identify the scent. Some fun smells to try this with are mint, lemon, maple, and anise.
If you try this, let me know how it worked out!