Believe it or not, scent is a very strong memory trigger. I read this years ago, and totally believe it. A roommate of mine was going to college and having a hard time. I told her to pick a perfume, cologne, or any pleasant smell and put it on a handkerchief.
I told her to keep it nearby while studying, so she could smell it. Then when having an exam at school, use that same scent again. It will help you remember what you studied! She didn't believe me, so ended up not doing very well.
I know it works, for a fact. When I was growing up, my dad would buy chunks of Pecorino Romano cheese and grate it himself. The smell would permeate the whole house. For those not familiar with this cheese, us kids called it Stink Cheese.
Years later, I was standing at the Deli in our local supermarket, and I had picked up a container of the cheese, already grated. As I was waiting my turn, I opened the container and took a sniff. The memories of my dad flooded back, and the tears started rolling down my cheeks.
For me, the smell of Ivory soap brings back memories too. When I smell it, I can see my brother and I in these big, rough textured tub/sinks that our Italian grandmother had in a room off her kitchen. She used to give us baths in these tubs, and scrub us with Ivory soap until we very nearly bled. (I used to swear that she used steel wool on us too, but I don't think that's true)
The memories come back, so very strong. I'm sure you all have your own stories, and memories.