Smell is also important to memory and emotion. Because smell is more specific than shapes or other thing you see, it intertwines more with memories. Studies show that for women especially they can identify the smell of their significant other.
Your brain forges a link between smell and memory, for example if you smell chorine you think of a pool. These memories also elicit emotions, which can explain why people’s preferred smells differ. Certain people may not like the smell or roses but they can’t recall a reason.
There are plenty of scents in our lives, which we associate with memories without even realizing it. Two very strong scents from my childhood are vanilla and fresh laundry. Both of these scents make me think of my mother. She used to wear vanilla when I was a small child, and I remember wanting to wear it too because I loved how it smelled. I also remember her wrapping me up in warm towels fresh from the dryer when I would help her do the laundry. This may explain why when it comes to choosing scented candles I always prefer clean scents like linen, it smells nice but is also calming.