well a certain smell.. combination of really bad breath and breath mints bring back... memories of my abuser.. it takes just the right combination.
It was diffcult, I worked with a man.. not every day thank goodness.. but he had the same "smell".. it wasn't like I thought beforehand when I saw him..
The smell "sunk" into my consiousness, I felt uneasy, then I had to concentrate and the knowledge would came to me...was a difficult thing.

My grandma was the most beloved person in my life, I lost her when I just turned 17.. She smelled always of "lilly of the valley", that smell always makes me feel so peaceful and safe..not sad..