Smells like memories

This morning something curious happened to me. I was going back home after finishing my Writing for Multimedia class when I opened the door of the stairs and I was transported to the past like in a flashback.

It was the smell, that smell that was hidden in the deepest area of my brain that made my memories of childhood came alive. I was 5 or 6 years old, maybe less, and the dad of my dad, my grandparent was working in the lab of a flour factory (they made flour with the wheat). I remember that visits to the lab, were we made little experiments to check the quality of the flour.

How can the stairs of the college smell like a flour factory of 15 years ago? How can that smell transported me to the past?

Is a mystery, but next time I go upstairs or downstairs I will try to discover.