Interestingly, smell has the ability to elicit a strong emotional response without the recollection of an explicit memory. Sometimes it’s just the feeling we recall.
When you encounter a smell tied to something meaningful in your past, you first feel the emotion followed by a cognitive recognition, information that was stored in your brain. Often that happens quickly, but sometimes it doesn’t happen at all, and other times it can happen after some extensive searching in your brain, Herz says.
— Cognitive neuroscientist Rachel Herz talks to Prevention. Read more in The Fascinating Reason Certain Smells Trigger Powerful and Emotional Memories.
I've been looking forward to Rachel Herz' book for a long time. I found out about her work on the psychology of smell several years ago, and although I never got around to reading her academic work (published in reputable journals like the American Journal of Psychology and Chemical Senses), I did keep track of her frequent interviews in the popular media. The Scent of Desire is her first book, and tackles a wide range of questions on the relation between emotion and olfaction. From odor-emotional conditioning and olfactive memory to cultural differences in odor familiarity, Herz explains how odors influence our social relationships and mental health. 
On yesterday’s Diane Rehm show, guest host Susan Page talked to Rachel Herz, author of