After a few months of training, odors began to come into focus for [Christine] Kelly. At first, they were terrible. “Everything had an unearthly, disgusting smell that would vacillate between burning Teflon frying pans [and] spoiling ham sandwiches that had been left inside a camper van in the rain for three months,” she recalls. Then, with continued training, Kelly was able to get a fix on lemon. More and more smells followed.

— Olfactory training can help people with anosmia recover their sense of smell. Read more at Regularly Whiffing Essential Oils Can Retrain Lost Sense of Smell at The Scientist. Hat tip to Janice!