Training your senses is training your brain. Your senses are by design adaptive. Smell training has gained wide interest since loss of smell is now recognized as a sign of COVID. The good news is these people might be more likely to produce the COVID antibodies.
Professor Thomas Hummel’s research in olfaction has shown that you can recover your sense of smell with training. You can buy the components to make your own kit in the links after the video. I recommend you use a 5th jar filled with coffee beans to use as a “palate cleanser” before you move onto the next scent. (Note these links are Amazon affiliate links, so I earn a small commission if you buy.)